Sand Cake Babka Piaskowa

Preheat oven to 350F. Separate the eggs. Mix the egg yolks with the sugar. In a separate bowl, mix the flours together and add the egg yolks, sugar, and almond essence. Add the baking powder, melted margarine, and yogurt and knead the dough thoroughly. Whip up the egg whites until stiff and fold them into the dough. Butter two 8x4 inch bread pans and sprinkle with breadcrumbs. Divide the mixture between the two pans. They should only be half-filled, as the mixture rises. Bake for 55 minutes