Preheat oven to 350 degrees.Line a 9 x 9 or 8 x 8 pan with aluminum foil. Lightly spray with cooking spray or grease with butter. Set aside.Stir cooled melted butter, granulated sugar, light brown sugar, cocoa, vanilla and eggs until combined.
Fold in flour and salt.
Pour batter into the prepared pan and bake for 25 minutes or until the edges of the brownies look set.
Allow the brownies to cool completely then frost with the chocolate ganache.Place back into the fridge to allow the ganache to set.
Serve with rainbow sprinkles on top! Slice and serve!
Chocolate Ganache
Add chocolate chips and heavy cream to a medium microwave safe bowl. Heat in 15 second intervals until fully melted. Set aside until ready to frost brownies.