Preheat your oven to 350°F (175°C) and prepare an 8” x 8” baking pan by lining it with parchment paper and spraying with non-stick spray.

In a large mixing bowl, combine the dry white cake mix, melted unsalted butter, large egg, and pure vanilla extract. Mix until just combined.

Gently fold in the white chocolate chips and red, white, and blue sprinkles.

Press 2/3 of the dough evenly into the bottom of the prepared baking pan.

Pour the sweetened condensed milk evenly over the dough base and spread it gently.

Flatten the remaining dough and lay it over the condensed milk layer, covering it completely.

Bake for 29 to 31 minutes until the center is set and edges are light golden brown.

Let cool in the pan for at least 60 minutes before slicing into 16 squares.