make 2 layer cake according to directions. Mix and cook flour and milk until thick. Don't leave this it thickens real fast and stir constantly...let cool while cake is baking. Beat butter, Crisco and sugar until fluffy....then add cooled floured mixture and beat in mixer about 4 min. Will be fluffy filling. Slice each layer in half(I use a long bread knife or you can use the string method) and layer the cake and filling but no filling on top. I put the can of icing in microwave for 10- 15 sec. before spreading on cake sides and top.
This is the favorite Birthday Cake for my family and friends! Enjoy!:>)