This is a building on recipes project so you will have to prepare your cake recipe and the buttercream according to the instructions on those recipe posts
If you are making homemade sprinkles be sure to start that project at least 1 full day ahead of time
The cakes pictured are baked in 3-7" cake pans
Take out about 1 cup of the buttercream to color for the confetti streamers and then remaining buttercream is for filling & icing the cake
Video
Notes
Vegan Vanilla birthday cake can be kept at room temperature for several days in a cool climate. For longer storage & to avoid the risk of flopping cakes, refrigerate for up to 1 week