# Components:
→ Chocolate Cake Batter
01 - 1 3/4 cups all-purpose flour
02 - 1/4 cup cornstarch
03 - 1 cup unsweetened cocoa powder
04 - 2 teaspoons baking soda
05 - 1 teaspoon baking powder
06 - 1/2 teaspoon kosher salt
07 - 1 cup granulated sugar
08 - 1 cup packed dark brown sugar
09 - 1/2 cup vegetable oil
10 - 1 cup mayonnaise
11 - 3 large eggs plus 1 egg yolk
12 - 1/2 cup milk
13 - 1 tablespoon vinegar
14 - 2 teaspoons vanilla extract
15 - 1 cup hot coffee or 1 cup hot water plus 2 teaspoons instant espresso powder
→ Chocolate Fudge Frosting
16 - 2 cups unsalted butter, at room temperature
17 - 1 1/2 cups powdered sugar
18 - 3 tablespoons corn syrup
19 - 1 teaspoon vanilla extract
20 - Pinch kosher salt
21 - 3/4 cup warm water
22 - 3/4 cup dutch process cocoa powder or unsweetened cocoa powder
23 - 10 ounces dark chocolate chips, melted and cooled slightly
# Directions:
01 - Preheat oven to 350°F. Grease the inside of three 8-inch cake pans and line the bottoms with parchment paper. Optionally, wrap pans with damp cake strips.
02 - In a medium bowl, whisk together flour, cornstarch, cocoa powder, baking soda, baking powder, and kosher salt. Set aside.
03 - Combine milk, vinegar, and vanilla extract in a liquid measuring cup and set aside.
04 - In a large bowl, whisk together granulated sugar, dark brown sugar, vegetable oil, and mayonnaise until smooth.
05 - Whisk in the eggs and egg yolk until fully blended.
06 - Pour the milk-vinegar-vanilla mixture into the batter and whisk to blend.
07 - Mix in half of the dry ingredient blend, then add hot coffee or espresso mixture and whisk thoroughly. Add the remaining dry ingredients and mix until the batter is smooth and thin.
08 - Evenly distribute the batter between the prepared pans. Bake for 30 to 35 minutes, or until a toothpick inserted in the center exits clean with a few moist crumbs.
09 - Let cakes cool in pans for 10 minutes. Run a knife around the edges, turn out onto a wire rack, and cool completely.
10 - Using a stand or hand mixer with paddle attachment, beat butter until creamy and smooth.
11 - Mix in powdered sugar, corn syrup, vanilla extract, and a pinch of salt. Scrape down bowl as needed.
12 - Whisk together warm water and cocoa powder, then pour into the frosting and mix to combine.
13 - Add melted, slightly cooled chocolate chips and mix until the frosting is smooth and glossy. If thin, chill frosting for 45 minutes in the refrigerator.
14 - After chilling, stir frosting firmly by hand with a rubber spatula until it holds its shape.
15 - Level the tops of cooled cake layers as needed using a serrated knife.
16 - Place one layer on a cake turntable and spread frosting over the top. Repeat with the remaining layers.
17 - Refrigerate the stacked cake for 20 minutes to allow layers to set.
18 - Frost the entire exterior of the cake until smooth. Slice and serve.
