Meanwhile, in 1-quart saucepan, heat 1/4 cup butter, 1/2 cup brown sugar and 2 tablespoons of the milk over medium-low heat, stirring frequently, until mixture just comes to a boil and sugar is dissolved. Stir in powdered sugar; beat with wire whisk if necessary to remove lumps. Immediately dip tops of cookies into glaze, or spread glaze on tops of cookies. (Cookies don’t need to be completely cooled, just firm and set.) Place on rack; let stand about 10 minutes until glaze is set. If glaze starts to set in saucepan, reheat over medium-low heat and beat with whisk until softened.