Gluten-Free Dark Chocolate Layer Cake

1. Preheat oven to 350 F (175 C). Prepare three 6-inch pans with butter, cocoa powder and a parchment circle on the bottom.
2. In a small bowl, mix together flour, xanthan gum (if using), dark cocoa, baking soda and baking powder.
3. In a large bowl cream together butter and sugars.
4. In another small bowl mix together the egg yolks, oil, buttermilk and vanilla.
5. Whisk the two egg whites until you reach soft peaks. (Or use a stand mixer for this.) Set aside.
6. Mix the batter together, alternating dry and wet ingredients. Add a third of the flour mixture to the bowl. Combine. Add half of the wet ingredients. Combine. Add another third of the flour mixture and combine again. Add the other half of the wet ingredients and then add the rest of the dry, mixing after each.
7. Add the warm coffee and mix to combine.
8. Fold in egg whites. Be gentle with the batter after this step, so as not to lose any air from the egg whites.
9. Divide the batter between the prepared 6” pans and bake at 350 F until done (about 25 minutes). When done, a toothpick inserted in the center will come out without wet better.
10. Let cakes cool in the pan for 15-20 minutes then move to cooling racks to cool completely before building a layer cake.