2 cups granulated sugar
2 cups all-purpose flour
3/4 cup unsweetened cocoa powder
1 1/2 teaspoons baking powder
1 1/2 teaspoons baking soda
1 teaspoon kosher salt
2 large eggs
1 cup buttermilk
1/2 cup vegetable oil
1 1/2 teaspoons vanilla extract
1 cup boiling water
4 oz semi-sweet chocolate, chopped
Preheat oven to 350°F and grease and flour two 9-inch round cake pans.
In a large bowl, whisk together the sugar, flour, cocoa powder, baking powder, baking soda, and salt.
Add the eggs, milk, oil, and vanilla, and beat on medium speed with an electric mixer for 2 minutes.
Gently stir in boiling water, then fold in chopped chocolate. Pour batter into the prepared pans. Bake until a toothpick inserted into the center comes out clean, 30-35 minutes.
Let cool in pan 10 minutes before inverting onto a wire rack to cool completely.
Note: To bake in a 9×13-inch baking dish, bake 35-40 minutes at 350°F.