Cream together shortening and sugar until fluffy. Add eggs. Beat 2 minutes at medium speed. Add bananas. Beat 2 minutes. Sift together dry ingredients, add to creamed mixture along with buttermilk and vanilla. Starting with flour. Beat 2 minutes. Stir in nuts.
Turn into 2 greased and floured 9 inch round layer cake pans. Sprinkle 1/2 cup coconut on each layer. For coffee cake sprinkle with 1/3 cup brown sugar. Bake in moderate, 350 to 375 degree oven, for 25 to 30 minutes. Cool.
For Creamy Nut Filling: Combine ingredients in heavy saucepan. Cook until thickened. Add pecans, salt and vanilla. Cool.
For White Snow Frosting: Cream together egg white, shortening, butter, coconut extract and vanilla. Gradually add powdered sugar, beating till light and fluffy.