Funfetti Cake Batter Blondies

Honestly the most amazing blondies i've ever seen/made. They taste like a funfetti cake and chocolate chip cookie put together with the texture of a brownie...

Ingredients:
1/2 cup unsalted butter, melted
1 egg
3/4 cup light brown sugar
1/4 cup granulated sugar
1 tablespoon vanilla extract
1 cup all-purpose flour
1/4 tsp salt
1/2 cup white chocolate chips
1/2 cup semi-sweet chocolate chips
1/4 cup rainbow-colored sprinkles, for batter
1 tbs rainbow-colored sprinkles, for sprinkling top surface

Preheat oven to 350 degrees. Line an 8-by-8-inch pan with aluminum foil, spray with cooking spray, set aside. 

In a medium microwave-safe bowl, melt the butter, about 90 seconds. Whisk together butter, egg, sugars, and vanilla in a medium bowl. 

Add the flour, salt, and stir until just combined. Fold in white and semi-sweet chocolate chips and 1/4 cup sprinkles. Pour batter into prepared pan, smoothing it lightly with a spatula or offset knife if necessary. 

Sprinkle with about 1 tablespoon additional sprinkles on top.

Bake for 20 - 24 minutes, or a toothpick comes out clean; do not overbake. Allow blondies to cool completely in pan before slicing and serving, at least one hour.