Cover a large, flat plate or cookie sheet with waxed paper and set aside.

Slice the butter into 8-10 pieces and add it to a large bowl.

Add the Funfetti cake mix, sugar, flour, and vanilla extract to the bowl.

Using a fork, work the butter into the flour and cake mix until thoroughly combined and resembles smooth cookie dough. Use hands to combine if needed.

Add 1-2 tablespoons of milk or water if the dough is too dry.

Mix in rainbow sprinkles.

Scoop 1 tablespoon of the truffle batter and roll it into a ball using your palms. Place the truffle balls on the prepared baking sheet.

Freeze the truffles for 10 minutes before coating them with white chocolate.

Melt white chocolate wafers in a microwave-safe bowl, microwaving for 30 seconds, stirring, then microwaving for another 20-30 seconds. Stir until fully melted.

Dip each dough ball into the melted white chocolate and place it on the prepared plate. Top with sprinkles immediately.

Place truffles in the fridge for at least 20-30 minutes or until the white chocolate coating hardens.

Store truffles in the fridge for up to 7-10 days. Serve and enjoy.