Preheat the oven to 350°F. Spray two 6-inch cake pans with baking spray. Line the bottoms with 6-inch parchment paper circles. Spray again.
In a medium bowl, sift the flour, cocoa powder, baking powder, and baking soda. Add the sugar and salt. Set aside.
1 cup All-purpose flour, ½ cup Unsweetened cocoa powder, ½ teaspoon Baking soda, 1 teaspoon Baking powder, ½ teaspoon Salt, ¾ cup White granulated sugar
Heat the water on the stove until steaming. In a separate bowl, add the eggs, oil, vanilla, and buttermilk. Then, slowly mix in the hot water. Go slow to not overcook the eggs.
2 Large eggs, ½ cup Oil, 1 teaspoon Pure vanilla extract, ½ cup Buttermilk, ½ cup Hot water
Add the wet ingredients to the dry and use a whisk to mix until just combined. Be sure not to over mix.
Pour the batter evenly between the two cake pans. Bake for 25-28 minutes until a toothpick inserted comes out clean.
Let the cakes sit in the hot pans for 10 minutes. Then, transfer to a cooling rack. Cool the cake completely before using.