Equipment
Ingredients
Vegan Buttermilk
- 360 ml unsweetened soy milk, room temperature
- 15 ml apple cider vinegar
Dry Cake Ingredients
- 250 g all-purpose flour
- 300 g granulated sugar
- 80 g dutch-processed cocoa powder, sifted
- 6 g baking powder
- 6 g baking soda
- 3 g fine sea salt
Wet Cake Ingredients
- 120 ml canola oil
- 10 ml vanilla extract
- 120 ml hot brewed coffee, hot
Peanut Butter Frosting
- 250 g creamy peanut butter
- 226 g vegan butter block, softened to room temperature
- 360 g powdered sugar, sifted
- 5 ml vanilla extract
- 30 ml unsweetened soy milk
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 638 kcal
- Protein
- 10 g
- Carbohydrates
- 84 g
- Fat
- 32 g
- Fiber
- 4 g
- Sugar
- 57 g
- Sodium
- 492 mg
- Saturated Fat
- 5 g
- Trans Fat
- 3 g
- Monounsaturated Fat
- 16 g
- Polyunsaturated Fat
- 9 g
- Potassium
- 440 mg
- Calcium
- 63 mg
- Iron
- 2.2 mg
- Magnesium
- 80 mg
- Phosphorus
- 202 mg
- Zinc
- 1.2 mg
- Vitamin A
- 7 mcg
- Vitamin E
- 4.7 mg
- Vitamin K
- 7 mcg
- Vitamin B6
- 0.1 mg
- Thiamin
- 0.10 mg
- Riboflavin
- 0.07 mg
- Niacin
- 3.5 mg
- Folate
- 20 mcg
- Water
- 20 g
- Alcohol
- 0 g
- Caffeine
- 9 mg
Sources: Aggregated Public Data, USDA FoodData Central
Method
Preheat the oven to 175 C / 350 F. Grease two 8-inch round cake pans and line the bottoms with parchment paper.
In a medium mixing bowl, whisk together the soy milk and apple cider vinegar. Set aside for 5 to 10 minutes to curdle and create a vegan buttermilk.
In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, Dutch-processed cocoa powder, baking powder, baking soda, and fine sea salt until fully incorporated.
Add the canola oil, vanilla extract, and the prepared vegan buttermilk to the dry ingredients. Whisk gently until just combined, being careful not to overmix.
Pour the hot brewed coffee into the batter. Whisk slowly until the batter is completely smooth and fluid.
Divide the batter evenly between the two prepared 8-inch round cake pans. Bake at 175 C / 350 F for 30 to 35 minutes.
Remove the cakes from the oven and let them rest in the pans for 10 minutes. Then, turn them out onto a cooling rack to cool completely.
While the cakes cool, prepare the frosting. Using an electric hand mixer, beat the softened vegan butter block and creamy peanut butter in a large mixing bowl until smooth and creamy.
Gradually add the sifted powdered sugar, about one third at a time, beating on low speed. Once incorporated, add the vanilla extract and soy milk, then beat on high speed for 2 minutes until light and fluffy.
Place one cooled cake layer on a serving plate or cake stand. Use a spatula to spread a generous layer of peanut butter frosting over the top. Place the second layer on top, then frost the top and sides of the entire cake.
Chef's Notes
- Hot coffee enhances the deep chocolate flavor without making the cake taste like coffee. If you prefer to avoid caffeine, hot decaf coffee or plain boiling water will yield an excellent texture.
- Always use block-style vegan butter for frosting rather than the spreadable tub variety. Tub varieties contain more water and less fat, which will cause your frosting to separate or become too soft.
- Sifting the cocoa powder and powdered sugar is not an optional step here. Dutch-processed cocoa powder is notoriously lumpy, and skipping the sifting will leave bitter pockets of dry powder in your cake and gritty frosting.
- If your cake layers dome significantly in the oven, use a serrated knife to carefully level the tops before assembling. This ensures a stable cake that will not slide or crack the frosting.
Storage
Refrigerator: 5 days — Store in an airtight cake dome to prevent the cake from drying out.
Freezer: 3 months — Freeze unfrosted cake layers wrapped tightly in plastic wrap. Frosting can be frozen separately.
Troubleshooting
Cake center sinks after baking
Cause: Oven door was opened too early during baking, or cake was underbaked.
Fix: Fill the sunken center with extra frosting before placing the top layer. It is a cosmetic issue and will still taste delicious.
Prevention: Do not open the oven door until at least 25 minutes into the baking time. Ensure the toothpick test is clear.
Frosting is too soft or splitting
Cause: Vegan butter was too warm or kitchen environment is too hot.
Fix: Place the mixing bowl in the refrigerator for 15 minutes, then re-whip until emulsified.
Prevention: Allow vegan butter to soften at room temperature just until it yields to a light press, do not let it get oily.
Cultural Context
The pairing of chocolate and peanut butter is a deeply cherished flavor profile in modern American dessert culture, famously popularized in the early 20th century by confectioneries like Reese's. This vegan adaptation honors the indulgence of traditional American layer cakes while utilizing plant-based substitutions, such as the reaction of vinegar and soy milk to mimic buttermilk, proving that decadent baking does not require animal products.
