Make the square 12 blocks LxW
Stack 3 more times with brown wall. Then it should be 4 blocks tall.
Make the cealing white wool
Now wreck the brown wool on the outside of the white.
Then replace it with white wool
This is what it should look like
Now wreck one block of the brown wool and replace it with white wool for the frosting on the cake
Do all the sides
Now on the very top wreck some of the white wool and replace it with red wool for the sprinkles
This is what your cake will look like! Thanks for watching I got a request from Minecraft Expert to make a cake shop put of it so check that out!