Ingredients:
2 cups all-purpose flour
1 cup granulated sugar
1 cup buttermilk
1/2 cup unsalted butter, softened
1/4 cup vegetable oil
2 large eggs
2 tablespoons black cocoa powder
1 tablespoon unsweetened cocoa powder
1 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
1 tablespoon white vinegar
1 teaspoon vanilla extract
Black food coloring (gel or paste)
Instructions:
Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans or line them with parchment paper for easy removal.
In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy. Add the vegetable oil and beat until well combined.
Beat in the eggs, one at a time, until fully incorporated. Mix in the vanilla extract and white vinegar.
In a separate bowl, sift together the all-purpose flour, black cocoa powder, unsweetened cocoa powder, baking powder, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk, beginning and ending with the dry ingredients. Mix until just combined, being careful not to overmix.
Add black food coloring to the batter, a few drops at a time, until you achieve the desired shade of black. Mix until the color is evenly distributed.
Divide the batter evenly between the prepared cake pans and smooth the tops with a spatula.
Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center of the cakes comes out clean.
Remove the cakes from the oven and let them cool in the pans for 10 minutes before transferring them to a wire rack to cool completely.