Minnehaha Cake

Directions

1. 1
   Cream butter; gradually add sugar, beating well. Add egg yolks, one at a time, beating well after each addition.
2. 2
   Combine flour, baking powder, and salt; add to creamed mixture alternately with milk, beginning and ending with flour mixture. Mix well after each addition. Stir in flavoring.
3. 3
   Beat egg whites (at room temperature) until stiff peaks form; fold into batter.
4. 4
   Spoon batter into 2 greased and floured 8-inch square pans. Bake at 350° for 45 minutes or until cake tests done. Cool in pans 10 minutes; remove layers from pans, and let cool completely. Spread frosting between layers and on top and sides of cake.