In a small bowl, whisk together the cinnamon, cayenne, nutmeg, allspice and salt. Set aside. 

In the bowl of a stand-up mixer with the paddle attachment, add the butter, powdered sugar, vanilla and heavy cream or milk. Mix on low until combined and smooth, about 3 minutes. Divide the frosting amongst three bowls (eyeballing this measurement is ok!). 

To the first bowl of frosting (this will be the darkest and most chocolate-y), add 5 tablespoons of melted chocolate and 1 teaspoon of the spice mixture. Mix until smooth and until the chocolate is thoroughly combined. 

To the second bowl of frosting (this will be a medium color), add 1 tablespoon of melted chocolate and 3/4 teaspoon of the spice mixture. Mix until smooth and until the chocolate is thoroughly combined. If you have any extra spice mixture (you shouldn’t have too much), divide it amongst the two chocolate frostings and mix. 

The third bowl of frosting should be kept white. This will be the lightest and brightest that we’ll use toward the top of the cake. 

To make the cake: Preheat oven to 350 degrees F. Next, butter and flour 4 (six-inch) cake pans. If you don’t have 4 pans, don’t worry, we can do this in batches of two. Set them aside. 

In the bowl of a stand-up mixer with the paddle attachment, add the butter, sugar and vanilla paste or extract. Beat until light and fluffy, about 3 minutes. 

In a large bowl, whisk together the cake flour, baking powder and salt. To a measuring cup, measure out the milk and whisk in the egg whites. 

To the stand-up mixer, add the flour and milk mixture, alternating between the two and ending with the milk. Beat until just mixed and combined, being sure not to over-mix! 

Divide the batter amongst four bowls (each will weigh 230 grams). To the first layer (the whitest and brightest), pour into the cake pan and smooth out the top with a spatula. 

To the second layer: mix in 1 1/2 teaspoons ScharffenBerger cocoa powder, along with 2 teaspoons of milk. Transfer to the cake pan and smooth out the top with a spatula. Transfer to the oven to bake for 17 to 20 minutes, until a skewer inserted into the center comes out clean. 

To the third layer: mix in 1 tablespoon ScharffenBerger cocoa powder, along with 1 1/2 tablespoons milk. Transfer to a prepared cake pan and smooth out the top. 

For the fourth layer (the most chocolate-y): mix in 3 tablespoons ScharffenBerger cocoa powder, along with 1 tablespoon milk and 1 tablespoon oil. Whisk until just smooth. Transfer to a prepared cake pan and smooth out the top. Bake the third and fourth layer for 17 to 20 minutes, until a skewer inserted into the center comes out clean. 

To assemble the cake, add the darkest layer to the base of a cake board or cutting board. Top with a few tablespoons of the most chocolatey frosting, smoothing it out to the edges. Repeat with the following layers, using the two lighter frostings. 

To make the ombre effect on the cake, add a few tablespoons of the super chocolate-y frosting to bottom half of the sides of the cake. And then, add a few tablespoons of lighter chocolate-y frosting to the middle part of the cake. Add the whitest to the top. Using a bench scraper, spin the cake at a medium speed and smooth out the sides. This could also be done with a big off-set spatula. 

Smooth out the top and sprinkle with a handful of cacao nibs and a sprinkling of pearl sugar. Slice and eat!