I dug my fork into the Blackout Cake to end all other chocolate cakes and emerged convinced that “moist as heck” and “sinful chocolate buttercream” were massive understatements.

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I am obsessed with this Blackout Cake because it actually delivers on chocolate intensity like nothing else. I love the way unsweetened cocoa powder layers into the batter and how hot strong brewed coffee wakes every chocolate note up.

The cake is absurdly moist, dense but soft, and the frosting lands like a glossy, sinful blanket that makes you forget polite manners. I adore tearing into it, crumbs everywhere, that blackout look irresistible.

But mostly I adore the eat-and-keep-eating loop it inspires. No pretense.

Just full-on chocolate that refuses to let you stop. Bring napkins and honest appetite for more.

Ingredients

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All purpose flour: the cake’s structure, keeps it tall and tender.
Granulated sugar: sweetness and a bit of lift, simple and reliable.
Unsweetened cocoa powder: deep chocolate backbone, bittersweet and dry.
Baking powder: gives rise, makes it light not dense.
Baking soda: reacts for browning and tender crumb, science magic.
Fine salt: balances sweetness, brightens chocolate notes.
Eggs: bind everything together and add richness.
Buttermilk: tangy moisture, keeps crumb soft and not gummy.
Sour cream: richness and slight tang, makes slices moist.
Neutral oil: keeps it tender and stays moist for days.
Hot coffee or espresso: deepens chocolate, makes it taste grown up.
Vanilla extract: rounds flavors, makes chocolate feel complete.
Chopped bittersweet chocolate: extra gooey richness, optional but nice.
Unsalted butter for frosting: super creamy base you’ll want to lick.
Powdered sugar: sweetens and firms frosting to spreadable perfection.
Unsweetened cocoa powder for frosting: adds real chocolate bite, not fake.
Heavy cream: smooths frosting, thins if it’s too stiff.
Vanilla in frosting: softens chocolate, gives warmth.
Fine salt in frosting: a pinch makes chocolate pop.
Reserved cake crumbs: classic blackout finish, rustic and dramatic.
Flaky sea salt optional: crunchy pop and contrast, seriously good.

Ingredient Quantities

2 1/2 cups (312 g) all purpose flour

1 3/4 cups (350 g) granulated sugar

3/4 cup (75 g) unsweetened cocoa powder, preferably Dutch process

2 tsp baking powder

1 1/2 tsp baking soda

1 tsp fine salt

2 large eggs, room temperature

1 cup (240 ml) buttermilk, room temperature

1/2 cup (120 ml) sour cream, room temperature

1/2 cup (120 ml) neutral oil (vegetable or canola)

1 cup (240 ml) hot strong brewed coffee or espresso

2 tsp vanilla extract

4 oz (115 g) bittersweet or semisweet chocolate, finely chopped, optional for extra richness

For the frosting: 1 1/2 cups (340 g) unsalted butter, softened

3 1/2 to 4 cups (420 to 480 g) powdered sugar, sifted

1 cup (100 g) unsweetened cocoa powder, sifted

1/4 cup (60 ml) heavy cream plus more if needed to thin

2 tsp vanilla extract

1/4 tsp fine salt, or to taste

To finish: about 1 to 1 1/2 cups of reserved chocolate cake crumbs (from trimming layers) for the classic blackout look

Optional: flaky sea salt for sprinkling

How to Make this

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1. Preheat oven to 350 F (175 C). Grease and line three 8 inch round pans with parchment, or two 9 inch pans if thats what you got, then lightly flour or cocoa dust them so cakes dont stick.

2. Whisk together flour, sugar, cocoa, baking powder, baking soda and salt in a big bowl until evenly mixed; set aside.

3. In another bowl whisk eggs, buttermilk, sour cream, oil and vanilla until smooth. Pour the wet into the dry and stir just until combined; dont overmix or the cake can get dense.

4. Stir the hot brewed coffee or espresso into the chopped chocolate (if using) until melted and glossy, then pour that mixture into the batter and fold gently until smooth. Batter will be fairly loose and chocolatey.

5. Divide batter evenly between pans and bake 25 to 35 minutes depending on pan size, or until a toothpick inserted near center comes out with a few moist crumbs. Let layers cool in pans 10 minutes, then invert onto racks to cool completely.

6. Meanwhile make the frosting: beat softened butter on medium speed until fluffy, about 2 to 3 minutes. Sift in cocoa powder, then gradually add powdered sugar with the mixer on low, alternating with heavy cream, until you reach a spreadable consistency. Beat in vanilla and salt, taste and adjust sweetness or salt. Add more cream if you need to thin.

7. Trim the cooled cake layers to level them and reserve about 1 to 1 1/2 cups of the trim as crumbs for the blackout coating. Save any irregular pieces to snack on, obviously.

8. Place first layer on your cake plate, spread about a third of the frosting, repeat with second layer and more frosting, then top with third layer and crumb coat the whole cake with a thin layer of frosting. Chill 15 to 30 minutes so the crumb coat firms up.

9. Apply the remaining frosting smoothly, then press the reserved cake crumbs onto the sides and top until the cake looks gloriously dark and even. If you want, sprinkle a tiny pinch of flaky sea salt over the top for contrast.

10. Chill briefly to set the frosting, then let the cake come to room temperature before slicing for best texture. Store leftovers covered in the fridge up to 4 days, bring to room temp before serving.

Equipment Needed

1. Oven (preheat to 350 F)
2. Three 8 inch round cake pans or two 9 inch pans, plus parchment paper to line them
3. Large mixing bowl and a medium bowl
4. Whisk and a silicone or rubber spatula (for folding and scraping)
5. Electric mixer or stand mixer for the frosting (hand whisk works but is tiring)
6. Measuring cups and spoons, and a kitchen scale if you got one
7. Fine mesh sieve or sifter for the cocoa and powdered sugar
8. Cooling racks and a cake plate or serving board
9. Serrated knife or cake leveler and an offset spatula for smoothing the frosting

FAQ

Q: Can I make the cake layers ahead of time? A: Yes. Bake the layers, cool completely, wrap tightly in plastic wrap and refrigerate up to 48 hours, or freeze up to 1 month. Thaw in the fridge overnight before trimming and frosting. Let layers come closer to room temp before assembling so frosting spreads easier.

Q: Do I have to use Dutch process cocoa? A: No, but Dutch gives a smoother, deeper chocolate flavor. If you only have natural cocoa, it will still be delicious but flavor and color can be a bit brighter. Don’t swap baking soda/powder amounts though; the recipe balances acidity with buttermilk and coffee.

Q: What can I use instead of buttermilk or sour cream? A: For buttermilk, stir 1 tbsp white vinegar or lemon juice into 1 cup milk, wait 5 minutes. For sour cream, plain Greek yogurt works well. Texture and tang stay pretty close, so dont worry.

Q: Is the chopped chocolate in the batter necessary? A: It is optional but recommended for extra richness and little pockets of molten chocolate. If you skip it, increase cocoa by 1 to 2 tbsp and stir batter well so it remains evenly chocolatey.

Q: My frosting is too thick or too thin, what do I do? A: If too thick add 1 tbsp heavy cream at a time until spreadable. If too thin add sifted powdered sugar 1/4 cup at a time until it holds shape. Chill 10 minutes if it gets too soft while assembling.

Q: How do I get the classic blackout look with cake crumbs? A: Trim domes and reserve the trimmings when leveling. Crumble them finely using your hands or a food processor, then press crumbs onto the frosted sides and top. For best adhesion, apply a thin crumb coat first, chill 20 minutes, then finish with final layer of frosting and press crumbs on.

The Best Chocolate Blackout Cake…Ever Recipe Substitutions and Variations

Buttermilk (1 cup)
- 1 cup milk + 1 tbsp white vinegar or lemon juice, let sit 5 minutes — same tang, same acidity for the leavener.
- 1 cup plain yogurt, thin with a splash of milk if too thick, keeps crumb tender.
- 1 cup kefir, straight swap, adds the same tang and moisture.
Large eggs (2)
- 2 flax eggs: 2 tbsp ground flax + 6 tbsp water, sit 5 min, good binder in cakes but crumb may be a touch denser.
- 1/2 cup applesauce (unsweetened), use in place of 2 eggs for moisture and some sweetness.
- 1/2 cup mashed banana, same as applesauce but will add banana flavor so pick carefully.
Neutral oil (1/2 cup)
- 1/2 cup melted unsalted butter, gives richer flavor but chill slightly before mixing so batter stays even.
- 1/2 cup applesauce for a lower-fat option, expect a slightly different crumb and less sheen.
- 1/2 cup avocado oil if you want a more neutral, slightly fruitier oil with good heat stability.
Unsalted butter for frosting (1 1/2 cups)
- 1 1/2 cups vegetable shortening + 2 tbsp butter for flavor, keeps frosting very stable for warm rooms.
- 1 1/4 cups cream cheese + 1/4 cup butter, for a tangy chocolate cream cheese frosting, slightly softer.
- 1 1/2 cups coconut oil, solid at cool temps, gives a coconut note and will be firmer at room temp.

Pro Tips

1) Make everything room temp first. Eggs, buttermilk and sour cream emulsify way better when theyre not cold, so your batter stays airy and the crumb will be tender. If you forget, pop eggs in warm water for 5 minutes.

2) Bloom the cocoa and melt the chocolate into the hot coffee off the heat. Stir until smooth and glossy before adding to the batter. That step deepens the chocolate flavor without making the batter gritty or oily.

3) Dont overmix once you combine wet and dry. Stir until just combined and no big streaks remain. Overworking develops gluten and gives a dense cake. A few small lumps are fine.

4) Use a thin crumb coat and chill it before the final frosting. That traps crumbs so the outer layer goes on clean, and pressing the reserved crumbs onto a slightly chilled frosting sticks much better. For super-smooth sides, warm a metal spatula with hot water, dry it, then smooth in long strokes.

5) Adjust frosting texture with cream, not more butter. If frosting is too stiff, add heavy cream a tablespoon at a time to loosen; if too thin, add a little sifted powdered sugar. Taste and add a tiny pinch of flaky sea salt to cut sweetness and make the chocolate pop. Store chilled and bring to room temp before serving for best flavor and texture.

The Best Chocolate Blackout Cake…Ever Recipe

Recipe by Samantha Dalling

0.0 from 0 votes

I dug my fork into the Blackout Cake to end all other chocolate cakes and emerged convinced that "moist as heck" and "sinful chocolate buttercream" were massive understatements.

Servings

servings

Calories

786

kcal

Equipment: 1. Oven (preheat to 350 F)
2. Three 8 inch round cake pans or two 9 inch pans, plus parchment paper to line them
3. Large mixing bowl and a medium bowl
4. Whisk and a silicone or rubber spatula (for folding and scraping)
5. Electric mixer or stand mixer for the frosting (hand whisk works but is tiring)
6. Measuring cups and spoons, and a kitchen scale if you got one
7. Fine mesh sieve or sifter for the cocoa and powdered sugar
8. Cooling racks and a cake plate or serving board
9. Serrated knife or cake leveler and an offset spatula for smoothing the frosting

Ingredients

2 1/2 cups (312 g) all purpose flour
1 3/4 cups (350 g) granulated sugar
3/4 cup (75 g) unsweetened cocoa powder, preferably Dutch process
2 tsp baking powder
1 1/2 tsp baking soda
1 tsp fine salt
2 large eggs, room temperature
1 cup (240 ml) buttermilk, room temperature
1/2 cup (120 ml) sour cream, room temperature
1/2 cup (120 ml) neutral oil (vegetable or canola)
1 cup (240 ml) hot strong brewed coffee or espresso
2 tsp vanilla extract
4 oz (115 g) bittersweet or semisweet chocolate, finely chopped, optional for extra richness
For the frosting: 1 1/2 cups (340 g) unsalted butter, softened
3 1/2 to 4 cups (420 to 480 g) powdered sugar, sifted
1 cup (100 g) unsweetened cocoa powder, sifted
1/4 cup (60 ml) heavy cream plus more if needed to thin
2 tsp vanilla extract
1/4 tsp fine salt, or to taste
To finish: about 1 to 1 1/2 cups of reserved chocolate cake crumbs (from trimming layers) for the classic blackout look
Optional: flaky sea salt for sprinkling

Directions

Preheat oven to 350 F (175 C). Grease and line three 8 inch round pans with parchment, or two 9 inch pans if thats what you got, then lightly flour or cocoa dust them so cakes dont stick.
Whisk together flour, sugar, cocoa, baking powder, baking soda and salt in a big bowl until evenly mixed; set aside.
In another bowl whisk eggs, buttermilk, sour cream, oil and vanilla until smooth. Pour the wet into the dry and stir just until combined; dont overmix or the cake can get dense.
Stir the hot brewed coffee or espresso into the chopped chocolate (if using) until melted and glossy, then pour that mixture into the batter and fold gently until smooth. Batter will be fairly loose and chocolatey.
Divide batter evenly between pans and bake 25 to 35 minutes depending on pan size, or until a toothpick inserted near center comes out with a few moist crumbs. Let layers cool in pans 10 minutes, then invert onto racks to cool completely.
Meanwhile make the frosting: beat softened butter on medium speed until fluffy, about 2 to 3 minutes. Sift in cocoa powder, then gradually add powdered sugar with the mixer on low, alternating with heavy cream, until you reach a spreadable consistency. Beat in vanilla and salt, taste and adjust sweetness or salt. Add more cream if you need to thin.
Trim the cooled cake layers to level them and reserve about 1 to 1 1/2 cups of the trim as crumbs for the blackout coating. Save any irregular pieces to snack on, obviously.
Place first layer on your cake plate, spread about a third of the frosting, repeat with second layer and more frosting, then top with third layer and crumb coat the whole cake with a thin layer of frosting. Chill 15 to 30 minutes so the crumb coat firms up.
Apply the remaining frosting smoothly, then press the reserved cake crumbs onto the sides and top until the cake looks gloriously dark and even. If you want, sprinkle a tiny pinch of flaky sea salt over the top for contrast.
Chill briefly to set the frosting, then let the cake come to room temperature before slicing for best texture. Store leftovers covered in the fridge up to 4 days, bring to room temp before serving.

Notes

Below you’ll find my best estimate of this recipe’s nutrition facts. Treat the numbers as a guide rather than a rule—great food should nourish both body and spirit. Figures are approximate, and the website owner assumes no liability for any inaccuracies in this recipe.