Step 1

BANANA CAKE: Sift the flour, baking powder, soda, and salt together in a bowl and set aside.

Step 2

Cream the shortening; gradually add sugar and continue creaming. Add beaten eggs and bananas and mix well.

Step 3

Add the flour mixture alternately with the combined buttermilk and vanilla, beginning and ending with the flour.

Step 4

Pour into two 9 inch layer pans that have been greased and floured. Bake at 375 for 25 to 30 minutes.

Step 5

BUTTERCREAM FROSTING: Heat milk until very hot but not boiling.

Step 6

Cream the butter and shortening until fluffy. Gradually add cornstarch and sugar. Beat well after each addition, then add vanilla.

Step 7

Add hot milk to sugar mixture a little at a time, beating thoroughly after each addition until all the sugar dissolves and it is thick enough to spread. It's very important to add the milk a little at a time or it will cause the frosting to curdle.