Grease a 9x13-inch pan with cooking spray or line it with parchment paper. Set aside.
In a microwave-safe bowl, heat the sugar cookie mix in 30-second intervals, stirring between each, until it reaches 160°F.
In a large pot over low heat, melt the butter.
Once melted, add the large marshmallows and stir continuously until smooth and fully melted.
Stir in the heated sugar cookie mix and vanilla extract until fully incorporated, then remove from heat.
Gently fold in the Rice Krispies, mini marshmallows, and 2 tablespoons of holiday sprinkles until evenly coated.
Transfer the mixture to the prepared pan and press down gently until flat.
Top with the remaining holiday sprinkles and let the treats sit for 30 minutes before cutting into squares.
Notes
Heat Treated*To heat-treat it, just pop the mix into a microwave-safe bowl and warm it up in 30-second bursts, stirring in between, until it hits 160°F. If you’d rather use the oven, spread a thin layer on a baking sheet and bake it at 300°F for about 10 minutes, or until it reaches that same temperature. Storage: You can store the Viral Sugar Cookie Rice Krispies Treats in an airtight container at room temperature for up to 3 days. Place parchment paper between the layers to prevent sticking. It’s not recommended to refrigerate the treats, as this can make them hard. For longer storage, individually wrap the squares tightly in plastic wrap, place them in a freezer-safe bag, and freeze for up to 6 weeks. Thaw at room temperature before serving.