In a large bowl, cream butter and brown sugar until light and fluffy. Beat in egg and root beer concentrate. Combine the flour, salt and baking soda; gradually add to creamed mixture and mix well.
Shape dough into 3/4-in. balls. Place 2 in. apart on ungreased baking sheets. Bake at 375° for 6-8 minutes or until lightly browned. Remove to wire racks to cool completely.
In a small bowl, beat the filling ingredients until smooth. Spread on the bottoms of half of the cookies; top with remaining cookies.
To Make Ahead: Package cookies in an airtight container, separating layers with waxed paper and freeze for up to 1 month. Thaw in a single layer before filling.
Editor's Note
This recipe was tested with McCormick root beer concentrate.
Every editorial product is independently selected, though we may be compensated or receive an affiliate commission if you buy something through our links.
