Soft and chewy Sugar Cookie Bars with a sweet buttercream frosting and plenty of sprinkles!
Preheat oven to 350F (175C) and prepare a 13x9 pan by lining with parchment paper (or lightly grease and flour the pan). Set aside.
Stir in vanilla extract.
Spread batter evenly into prepared pan and bake on 350F (175C) for 25-30 minutes or until center is set and edges are beginning to turn light golden brown.. Allow cookie bars to cool completely in pan before covering with frosting.
Place butter in a large bowl and beat with an electric mixer until cream.
Gradually add sugar until completely combined.
Stir in vanilla extract and salt, stir until well-combined.
Spread over completely cooled sugar cookie bars. Decorate with sprinkles, cut into squares and serve.