Butter Sponge Cake

This batter must be made in the early evening and set to rise in a warm place until morning. Mix together the dissolved yeast cake, mashed potatoes and 1/2 cup of the sugar. Let stand for four hours. To the scalded milk, add the butter and stir until melted. When cool add the eggs, 1/2 cup of sugar, and salt and combine with the yeast mixture. Sift in the flour and knead thoroughly. Cover and let rise in a warm place until morning. Roll out to about 1/4 inch thick, brush the dough with melted butter and cut in 2 inch squares. Turn up the four corners toward the center. Place on a greased baking sheet about 2 inches apart and let rise until light. Bake at 450?F for 20 minutes. Remove from oven, brush with melted butter, and sprinkle with powdered sugar. Serve hot with plenty of coffee.