Banana Streusel Coffee Cake

In a small mixing bowl, beat egg whites until soft peaks form; set aside. In a large mixing bowl, cream shortening and sugar. Beat in egg yolks; mix well. Add bananas. Combine flour and baking soda; add to creamed mixture alternately with milk, beating well after each addition. Add vanilla. Fold in egg whites. Fold in nuts if desired. Pour into a greased 13x9x2" baking pan. Bake at 350 degrees for 45-50 minutes. Cool on a wire rack. If desired, garnish with a dollop of whipped cream and a few banana slices.

* = To sour milk, place 1 tsp. white vinegar in a measuring cup. Add enough milk to equal 1/4 cup