Preheat oven to 350 degrees. Line and spray two 9 inch round cake pans. Make sure they are lined and sprayed. The whey protein makes the batter sticky
In a medium mixing bowl whisk together almond flour, coconut flour, whey protein powder, xanthan gum, cocoa powder, and salt until combined and no lumps in the cocoa or flour. Set aside
In a large mixer bowl combine butter and monkfruit sweetener. Beat on low 10 seconds then on medium 3 minutes or until creamy and fluffy.
Add eggs one at a time. Beat on low about 10 seconds after each addition or just until each egg is combined
Scrape down sides. Add sour cream, milk, vanilla and vinegar. Beat on low 10 seconds or until just combined.
Add half of the dry ingredients and beat on low about 10 seconds or just until the dry ingredients are wet.
Add the remaining dry ingredients Beat on low 10-15 seconds or just until combined. Let batter sit for 3 minutes to allow the xanthan gum to bind the ingredients and the coconut flour can absorb some of the moisture.
Add baking soda, baking powder and red food coloring. Make sure the baking powder and soda are added after the batter has set for optimum rise in cake. Beat on low 10 seconds or until just combined.
Divide batter evenly between the prepared cake pans ( roughly about 2 cups batter in each pan) Use spatula and smooth the batter evenly across the pans
Bake 35-40 minutes or until tester comes out clean. Let cool in pans for 15 minutes
Gently loosen the cakes from the sides of the pans with a butter knife. Let cool in the pans at least one more hour. Carefully turn cakes onto wire racks to cool completely before frosting