Ingredients
- 1 3/4 cup all-purpose flour (205g)
- 1 cup brown sugar packed (200g)
- 1 cup sugar (200g)
- 3/4 cup natural cocoa powder (75g)
- 1 1/2 teaspoon baking soda
- 3/4 teaspoon salt
- 1/2 cup unsalted butter melted (113g)
- 1/2 cup canola oil (may substitute vegetable oil) (118ml)
- 2 large eggs + 1 egg yolk room temperature preferred
- 2 teaspoons vanilla extract
- 1 cup buttermilk
- 1/2 cup hot coffee (or 1 teaspoon instant coffee dissolved into 1/2 cup hot water) (118ml)
- Silky Chocolate Buttercream
- 1 cup semisweet chocolate chips (170g)
- 1 cup unsalted butter softened to room temperature (226g)
- 2 cups powdered sugar (320g)
- 1/2 teaspoon vanilla extract
- 1/2 teaspoon salt
- 2 Tablespoons heavy cream (30ml)
- 3/4 cup mini chocolate chips optional
Preparation
Step 1
Preheat oven to 350F (177C) and prepare two deep 8" round cake pans by lining the bottoms with parchment paper and lightly greasing the sides. Set aside.
In the bowl of a stand mixer fitted with a paddle attachment, whisk together flour, sugars, cocoa powder, baking soda, and salt.
Add melted butter and oil, stir well.
Add eggs and egg yolk, one at a time, stirring well after each addition. Pause occasionally to scrape down sides and bottom of bowl.
Stir in vanilla extract. Gradually add buttermilk and stir well.
Add hot coffee, stirring until ingredients are well-combined (be sure to scrape sides and bottom of bowl again).
Evenly divide batter between prepared pans. Bake on 350F (177C) for 35-40 minutes (toothpick inserted in center should come out with moist crumbs).
Allow to cool for 15 minutes before inverting onto cooling rack to cool completely before frosting.
Chocolate Buttercream Frosting
In a microwave-safe bowl, microwave chocolate chips at 15 second intervals, stirring between intervals, until chips are completely melted. Set aside and allow to cool slightly (about 10 minutes, stirring occasionally).
Cream room temperature butter with an electric mixer. Stir in slightly cooled chocolate and beat well.
Gradually add sugar, scraping down the sides and bottom of bowl occasionally.
Sprinkle in salt and vanilla extract, stir well.
Gradually add heavy cream, increase speed to high and beat for 1 minute.
Spread a thick layer of frosting over the top of one cake round and sprinkle with mini chocolate chips. Top with second cake round and evenly frost cake. Slice and serve.