Preheat your oven to 350°F.
Line an 8x8 baking dish with parchment paper.
In a large bowl, mix together all the brownie ingredients until well combined.
Pour the batter into the prepared baking dish and spread it evenly.
Bake for 19-22 minutes or until a toothpick inserted into the center comes out clean.
While the brownies are baking, prepare the frosting by mixing all the frosting ingredients until smooth.
Once the brownies have cooled completely, spread the frosting evenly over the top.
Sprinkle with rainbow sprinkles for an extra pop of color.
Slice, serve, and enjoy every decadent bite!