Rainbow whoopie pies featuring rainbow buttercream sandwiched between a pair of soft vanilla cakes, plus even more rainbow sprinkles on top.

Sandwich cookies featuring a pair of heart-shaped funfetti sugar cookies with swirls of rainbow buttercream in between.

An easy rainbow buttercream frosting recipe for decorating cakes, cupcakes, macarons, and whoopie pies.

Wanna learn how to make rainbows?

Buttercream Sandwich Cookie Recipe. Crispy sugar cookies sandwiching sweet buttercream.