July 4th Cookie Bars

Ingredients

• ¾ cup salted butter melted
• 1 cup light brown sugar
• ⅓ cup granulated sugar
• 1 tbsp vanilla extract
• 2 eggs at room temperature
• 2 cups all-purpose flour
• 1 tbsp cornstarch
• ½ tsp baking soda
• ½ tsp salt
• 1 cup red white & blue M&Ms
• ½ cup red white & blue sprinkles
• ¾ cup milk chocolate chips
• ¾ cup salted butter at room temperature
• 4 cups powdered sugar
• 1 tsp vanilla extract
• 3-5 tbsp heavy cream or milk at room temperature