ok here's how you do it:
1. shoot the confetti gun near the special frosting machines (the ones closest to the noob)
2. put the cake/s it shoots out in the frosting machine/s
3. repeat
it should give you cake with a star above it. if it doesn't have a star above it you either:
1. are not the person putting the cake in the machine
2. did not put it in right (it fell off the edge basically)