Gather 3 milk buckets, 2 sugar, 1 egg, and 3 wheat
Open a crafting table
Place 1 milk bucket in the top-left, top-middle, and top-right slots
Place 1 sugar in the middle-left and middle-right slots
Place 1 egg in the center slot
Place 1 wheat in the bottom-left, bottom-middle, and bottom-right slots
Take the cake from the result slot
Place the cake on a solid block to use it
Eat slices from the cake by right-clicking or using the interact button