Preheat your oven to 300°F (150°C). Spread the funfetti cake mix evenly on a baking sheet and bake for 5-10 minutes, stirring halfway through. Let it cool while you prepare the batter.

In a medium saucepan over low heat, melt 1/2 cup of butter. Once melted, add 1 cup of white chocolate chips and 1/2 cup of sweetened condensed milk. Stir continuously for about 3-5 minutes until the mixture is completely smooth.

Lower the heat and stir in 1 teaspoon of vanilla extract. Gradually add the cooled, heat-treated cake mix and 1/2 cup of sprinkles, mixing until fully integrated.

Line an 8x8-inch baking dish with parchment paper. Pour the cake mixture into the dish, spreading it evenly, compacting it and refrigerate for 1 hour until set.

Remove the chilled mixture and cut it into small squares. In a microwave-safe bowl, melt 1 cup of vanilla melting wafers in 30-second bursts. Dip each square into the melted coating and sprinkle with additional sprinkles before the chocolate hardens.