Pop the Popcorn: Begin by popping 7 cups of popcorn using your preferred method—stovetop, microwave, or an air popper. Remove any unpopped kernels and let cool slightly.

Melt the Marshmallows: In a large saucepan, melt 3 tablespoons of butter over low heat. Add 50 marshmallows and stir continuously for 3-5 minutes until completely melted and smooth.

Add Flavorings: Remove the saucepan from heat and stir in 1 teaspoon of vanilla extract. Mix in the cake batter protein powder if using.

Combine Popcorn and Marshmallow Mix: Pour the melted marshmallow mixture over the popcorn. Toss gently until popcorn is well-coated.

Fold in the Funfetti: Add a handful of Funfetti sprinkles and fold them into the mixture evenly.

Set the Treats: Transfer the mixture to a parchment-lined baking dish and press down firmly. Allow to cool for about 30 minutes or refrigerate for 15-20 minutes.

Optional Chocolate Drizzle: Melt white chocolate and drizzle over the chilled treats, adding more sprinkles while the chocolate is wet.