Cream butter, sugar and egg yolks. Soak poppy seeds in buttermilk. Sift dry ingredients ( flour, baking soda, baking powder, and salt). Alternately add buttermilk and dry ingredients to the creamed mixture. Fold in stiffly beaten egg whites flavored with almond. In a small bowl, combine 1/2 cup sugar, 1 Tblsp. cinnamon. Pour half the cake batter into a greased tube pan. Cover with part of the cinnamon sugar mixture. Pour in remaining cake batter and sprinkle with remaining cinnamon sugar mixture. Bake for 1 hour at 350*.