In the bowl of a stand mixer, cream butter and sugar together until fluffy, about 3 minutes. Meanwhile, whisk together flour, salt and baking powder in a large bowl. To make the cake batter, add the flour mixture and the buttermilk to the creamed butter, alternating between wet and dry ingredients and beating after each addition After everything is well mixed, add the vanilla and almond extracts, mix again to incorporate, and then fold in the beaten egg whites until the batter is smooth. Fold in the sprinkles. Try to be very gentle, if you over mix, color from the sprinkles will begin to bleed. Divide evenly between the prepared pans, smooth the top of the batter, and bake for approximately 30 minutes or until a toothpick inserted into the center comes out clean. Cool the cakes completely on cooling racks, then remove from the baking pans and discard the parchment.