preheat oven to 350°F

generously spray cake pan with nonstick cooking spray

with electric mixer beat butter until smoothe about 2 minutes add sugar and continue beating about 5 minutes more.

combine egg and egg white and add in 2 batches beating well after each addition.combine milk and vanilla in a bowl, combine flour baking powder and salt in another bowl.

reduce mixer speed to lowand add flour mixture in 3 bbatches, alternating with the milk mixture begining and ending with the flour.Beat each addition just until incorporated, stopping the mixer to scrape sides of the bowl.

fill the wells of the. special cake pan 1/2 full bake for 15 minutes, or until the center springs back or toothpick comes out clean.let cool about 15 minutes.invert onto rack tap pan gently and pull pan up.cool compleytly before filling.use a piping bag with a narrow tip and fill in 3 spots on top of cake.

Vanilla Fluff Filling

in a bowl beat the butter with confectiners sugar, marshmellow fluff. and heavy cream at medium speed until fluffy

note: this is from a cildrens kit for making hostess brand cakes, for ages 6 and up.manufactured by Interstate bakeries corporation.