M&M COOKIE BARS
1 cup unsalted butter (at room temperature)
1 cup light brown sugar, packed
¾ cup granulated sugar
2 large eggs
2 teaspoons vanilla extract
3 cups all-purpose flour
1 teaspoon baking soda
1 teaspoon Kosher salt
1 cup chocolate chips (plus more for tops if desired)
1 cup M&M’s (plus more for tops if desired)