Step 1

Combine flour, cocoa, baking powder and salt in bowl; mix well. Set aside.

Step 2

Combine 1 1/4 cups powdered sugar and 3/4 cup butter in bowl; beat at medium speed until creamy. Add egg and vanilla; continue beating until well mixed. Gradually add flour mixture; beat at low speed until well mixed.

Step 3

Divide dough in half. Shape each half into ball; flatten slightly. Wrap each in plastic food wrap. Refrigerate at least 2 hours or until firm.

Step 4

Heat oven to 375°F.

Step 5

Roll out 1 dough half on cocoa powder-dusted surface to 1/8-inch thickness. (Keep remaining dough half in refrigerator.) Cut with 2-inch round cookie cutter. Place, 1 inch apart, onto parchment-lined cookie sheets. Bake 8-10 minutes or until set. Remove to cooling rack to cool completely. Repeat with remaining dough half.

Step 6

Beat 1/2 cup butter and shortening in bowl until creamy. Add powdered sugar and peppermint flavoring. Beat at low speed until well mixed.

Step 7

Spread 2 teaspoons filling onto bottom side of one cookie; top with another cookie, bottom-side down. Store covered.