INGREDIENTS
1 cup
plus 1 tbsp. (5¼ oz.) all-purpose flour
1/4
tsp. baking soda
1/4
tsp. salt
6 tbsp
unsalted butter, melted and cooled until warm
1/2
cup (3½ oz.) packed brown sugar
1/4
cup (1¾ oz.) granulated sugar
1/2
large egg plus ½ egg yolk (or 1 medium egg)
1 tsp
vanilla extract
1/2
cups mini M&Ms, plus extra for topping
6 1/2 tbsp
unsalted butter, at room temperature
3/4
cup confectioners’ sugar, sifted
salt
1 1/2 tbsp
heavy cream
3/4
tsp. vanilla extract