Triple-Layer Chocolate Peanut Butter Cake with Ganache

Ingredients

Tick the ingredients as you go

Cake

• 1 3/4 cups (219g) all-purpose flour, spooned and leveled
• 3/4 cup (64g) unsweetened natural cocoa powder
• 1 3/4 cups (350g) granulated sugar
• 2 tsp baking soda
• 1 tsp baking powder
• 1 tsp salt
• 2 tsp instant espresso powder (optional)
• 1/2 cup (113g/120ml) canola or vegetable oil
• 2 large eggs, room temperature
• 3/4 cup (180g) full-fat sour cream, room temperature
• 1/2 cup (120g/ml) buttermilk, room temperature
• 2 tsp pure vanilla extract
• 1/2 cup (120g/ml) hot water or black coffee
• 1 cup (170g) mini semi-sweet chocolate chips, tossed in 1 Tbsp flour

Peanut butter frosting

• 3/4 cup (12 Tbsp; 170g) unsalted butter, softened
• 1 3/4 cups (440g) creamy peanut butter
• 1 3/4 cups (210g) confectioners' sugar
• 1 tsp pure vanilla extract
• Pinch of salt
• 3 Tbsp (45g/ml) heavy cream, room temperature

Chocolate ganache

• 8 oz (226g) semi-sweet chocolate, finely chopped
• 1 cup (240g/ml) heavy cream
• Optional garnish: chopped or mini peanut butter cups

Instructions

1. 1

   Heat the oven to 350°F (177°C). Grease the three cake pans, line the bottoms with parchment rounds, and grease the parchment.

2. 2

   Whisk the flour, cocoa, sugar, baking soda, baking powder, salt and espresso powder together. In a separate bowl, beat the oil, eggs and sour cream, then beat in the buttermilk and vanilla. Add the wet ingredients to the dry, pour in the hot water or coffee, and mix until smooth. Fold in the flour-coated chocolate chips. You should have about 6–6.5 cups (about 1400g) of batter; divide it evenly among the pans.

3. 3

   Bake for 24–26 minutes, until a toothpick inserted in the center comes out clean. Let the layers cool in their pans for 1 hour, then turn them out, peel off the parchment, and let them finish cooling. A slight dip in the centers is normal.

   
4. 4

   For the frosting, beat the butter for about 2 minutes, then add the peanut butter and beat for 1–2 minutes more. Add the confectioners' sugar, vanilla and salt, then the cream with the mixer on low. Increase to medium-high and beat for 1–2 minutes. If it seems thin, beat in up to 1/4 cup more confectioners' sugar. You will have about 3.5–4 cups (850g).

6. 5

   Set one layer on a serving plate and spread about 1 cup of frosting over it. Add the second layer and another cup of frosting, then the third layer. Cover the top and sides with a thin crumb coat, smooth it with a bench scraper, and refrigerate uncovered for 30 minutes to 3 hours.

   
7. 6

   For the ganache, heat the cream just until it simmers (do not let it boil). Pour it over the chopped chocolate, wait 2–3 minutes, then stir slowly until smooth. Refrigerate for 30 minutes to 1 hour, until thickened.

8. 7

   Pour or spoon the thickened ganache over the chilled cake and smooth it over the top and sides. If you like, pipe the leftover frosting around the top edge with a large open star tip and decorate with peanut butter cups. Serve right away or refrigerate for up to 4–6 hours. It can be served chilled or at room temperature.

   
9. 8

   Cover and refrigerate leftovers for up to 5 days.