1. Preheat oven to 375°.
2. In a large mixing bowl, combine sugars, butter, shortening, buttermilk, eggs, root beer extract and vanilla; beat with an electric mixer on medium speed until well blended.
3. Stir in flour, soda and salt; continue beating on low speed until a soft dough forms.
4. Scoop rounded tablespoons of dough 2" apart onto parchment-lined baking sheets; bake in preheated oven until centers are set (10-12 min.), rotating baking sheets halfway through.
5. Transfer cookies onto a wire cooling rack to cool completely.
6. Place a scoop of ice cream on half of the cookies; sandwich with remaining cookies.
7. Place ice cream sandwiches on a parchment-lined baking sheet; freeze, covered, until ready to serve.

Tasty Tip:

• Cookie may be frosted rather than made into sandwiches. To make frosting, beat 4 cups confectioners' sugar, 4 tbsp. half-and-half and 4 tsp. root beer extract until frosting is of spreading consistency, adding additional half-and-half if needed.