INGREDIENTS
1 cup
butter
1 1/2 cups
brown sugar (packed)
1
large egg
1
egg yolk
1 tbsp
vanilla extract
2 cups
all-purpose flour
1 cup
whole wheat flour
1 tsp
baking soda
3/4 tsp
kosher salt (or scant 1/2 tsp. table salt)
1 cup
semisweet mini chocolate chips
3/4 cup
marshmallow bits