Prepare three 8"x2" cake pans with cake goop or another preferred pan spray. Preheat your oven to 335ºF
Heat your water until simmering and then combine with your cocoa powder. Stir until cocoa powder is moistened. It will look lumpy but that is normal. Set it aside and let it cool while you prepare the cake batter.
Combine 3/4 cup of the milk and the oil together and set aside.
Combine the remaining milk, eggs, vanilla, and almond extract together, whisk to break up the eggs and set aside.
In the bowl of your stand mixer, combine the flour, sugar, baking powder, baking soda, and salt with the paddle attachment. Mix 10 seconds to combine.
Add your softened butter to the flour mixture and mix on low until mixture resembles coarse sand (about 30 seconds).
Add in your milk/oil mixture and mix on low until dry ingredients are moistened. Then increase the speed to medium (setting 4 on my KitchenAid) and let it mix for 2 minutes to develop the cake's structure. If you don't let your cake mix on this step your cake could collapse.
Scrape your bowl and then reduce speed to low. Add in your egg mixture in three batches, letting the batter mix for 15 seconds between additions.
Scrape down the sides again to make sure everything has incorporated.
Take out 1/3 of your batter and combine it with the cooled chocolate mixture and fold gently until combined.
Layer your batter into your pans, starting with vanilla, then chocolate and ending with vanilla. Use a butter knife to swirl together gently. Do not over-mix or your cake will not have a marbled interior.
Bake 35-40 minutes at 335ºF until a toothpick inserted into the center comes out cleanly but the cake has not begun to shrink yet from the sides of the pan. IMMEDIATELY TAP PAN FIRMLY on countertop once to release the steam from the cake. This stops the cake from shrinking.
Let cakes cool for 10 minutes inside the pan before flipping them out. The cake will shrink a bit and that is normal. Flip onto a cooling rack and let cool fully. I chill my cakes before handling or you can wrap them in plastic wrap and freeze them to trap moisture in the cake. Thaw on the countertop while still wrapped before frosting.