In a microwave-safe bowl, add the peanut butter and honey together. Microwave for 20-30 seconds until softened and runny. Stir until smooth.

Gradually add the vanilla protein powder and stir until a stiff dough forms. Adjust texture with milk or water as necessary.

Fold in the rainbow sprinkles carefully, ensuring not to overmix.

Using a tablespoon or cookie scoop, measure portions of the dough and roll between palms to form balls.

Roll each ball in extra sprinkles and place on a parchment-lined tray.

Refrigerate for about 20 minutes to firm up the protein balls.

After chilling, store in an airtight container in the fridge for up to a week or freeze for longer storage.