Preheat the oven to 335º F/168º C.

Prepare two three 6"x2" cake pans with cake goop or another preferred pan spray. Fill pans about ¾ full with batter.

Combine flour, sugar, baking powder, baking soda, and salt in a stand mixer and mix for 10 seconds.

Combine ½ cup of the buttermilk and the oil, then set aside.

Whisk together the remaining buttermilk, egg whites, food coloring, and vanilla, then set aside.

Add softened butter to the dry ingredients and mix on low until it resembles coarse sand (about 30 seconds). Add the milk/oil mixture and mix until moistened, then increase to medium and mix for 2 minutes.

Scrape the bowl and reduce speed to low. Gradually add the egg white mixture in three batches, mixing for 15 seconds between each addition.

Scrape down the sides and pour the batter into the prepared pans.

Bake for 35-40 minutes until a toothpick comes out clean. Tap the pan on the countertop to release steam.

Let the cakes cool in the pans for 10 minutes before flipping them onto a cooling rack.

Sprinkle gelatin over cold water and let bloom for 5 minutes.

Melt gelatin in the microwave for about 5 seconds.

In a cold mixing bowl, whip heavy cream to soft peaks.

Add powdered sugar and vanilla, mixing until combined.

Drizzle in the gelatin while mixing until stiff peaks form.