INGREDIENTS
3/4 cup
butter, softened
3/4 cup
light brown sugar, packed
1/4 cup
granulated sugar
1
large egg
2 tsp
vanilla
2 cups
all-purpose flour
2 tsp
cornstarch
1 tsp
baking soda
1/4 tsp
salt
2 cups
milk chocolate M&M's, divided
1/2 cup
milk chocolate chips