Grease and flour (or sugar) a 9 X 13 inch pan or two 9-inch layer pans. Sift the cake flour, baking powder and salt. Cream butter in a large bowl; gradually, add sugar while creaming at high speed of mixer. Continue until light and fluffy. Add vanilla.
At medium speed, add eggs one at a time, beating well after each addition. At low speed, blend in dry ingredients alternately with milk, beginning and ending with dry ingredients. Mix well. Pour batter into pan(s) and bake at 350 degrees for 35 to 40 minutes, until cake is lightly brown and springs back when touched in center.
I have mashed a couple of dead bananas and added them and cut back on the milk by a half cup. I have also added a teaspoon of vinegar to the milk.