LINE a cookie sheet with Reynolds Parchment Paper; set aside. COMBINE flour, baking powder and salt on a sheet of parchment paper; set aside. Beat butter and sugar until fluffy in a large bowl, with an electric mixer. Mix in egg and lemon extract until well blended. Gradually beat flour mixture into butter mixture until smooth. Divide dough in half; shape into 2 flat disks. Wrap dough in Reynolds Seal-Tight Plastic Wrap; refrigerate 30 minutes to 1 hour or until firm enough to roll. TO BAKE, preheat oven to 375¢ªF. Roll out dough 1/8 inch thick between 2 lightly floured sheets of parchment paper or on a lightly floured surface. Cut dough with 2 to 6 inch snowflake cookie cutters. Place cookies 1-inch apart on parchment-lined cookie sheet. Decorate with colored sprinkles. BAKE 8 to 10 minutes or until cookies are just beginning to brown on edges. Cool. MIX powdered sugar and milk together in a small bowl, adding milk slowly until desired consistency is reached. Drizzle over cooled cookies. REYNOLDS KITCHENS TIP: Rolling out cookie dough between 2 lightly floured sheets of parchment paper prevents sticking and keeps work surface clean. To hold parchment sheets in place, fold a few inches of parchment over edge of counter, lean against them while you are rolling dough. If necessary, turn parchment to roll dough at different angles. Substitute lemon juice for milk for extra lemon flavor.