Preheat the oven to 350 degrees Fahrenheit. Spray two 8-inch round cake pans with pan spray and add a parchment round to the bottom. Spray the parchment with pan spray and set aside.

Add both sugars and vegetable oil to a large mixing bowl and beat with a hand mixer or the paddle attachment until combined. Add the eggs and vanilla and mix until combined.

In a medium bowl, whisk together the black cocoa powder, regular cocoa powder, flour, baking soda, baking powder, and salt. Add the dry ingredients to the wet in 3 increments while mixing on low speed. Once all the dry ingredients have been added, mix on medium speed until fully combined.

Scrape down the sides and bottom of the bowl and add the buttermilk and sour cream. Mix until combined. Add the hot coffee and mix until combined.

Divide the batter evenly into the two prepared cake pans and bake for 40-45 minutes, until the tops of the cakes spring back when gently pressed and a toothpick comes out clean from the center.

Let the cakes cool for 5-10 minutes before inverting them on a cooling rack. Let cool completely before serving.

Remove from the heat and transfer to a heat-proof bowl. Cover with plastic wrap and chill in the fridge for at least 40 minutes

Add the room-temperature butter to a stand mixer and whip with the whisk attachment for about 8 minutes, until the butter is light and fluffy.

Add the flour mixture to the butter one scoop at a time until it is all incorporated

Scrape down the sides and bottom of the bowl and switch to the paddle attachment. Add the vanilla and salt and beat on medium-high for 10-13 minutes, until smooth and fluffy.