Sift together flour, baking powder, soda and salt. Stir into butter mixture, alternating with sour cream. Stir together well to combine but do not overbeat.

Spread 1/2 of batter into the bottoms of 2 greased and lightly floured pans (1/4 of the batter for each pan bottom layer).

Next, in each pan, spread a layer of filler, then top with other half of batter.

Bake 60 minutes at 350 degrees.

Makes 2 pans 9 x 5 x 3 inches, 14 to 16 servings.