A piped cookie from Martha Stewart. These look great so I'm putting the recipe here for safe keeping. Martha had them piped into bows, but I'm sure any shape would work. I'm guessing on the yield since one was not given.
Put butter and cream cheese in the bowl of an electric mixer fitted with the paddle attachment; mix on medium speed until creamy.
Mix in granulated sugar. Add egg, and lemon zest and juice; mix well. Sift together flour, baking powder, and salt into a medium bowl; mix into butter mixture on low speed.
Preheat oven to 375 degrees. Place a small amount of the dough in a pastry bag fitted with a large French tip (such as Ateco #865). Holding tip very close to the surface, pipe 3 1/2-inch bows onto baking sheets lined with parchment paper; space 1 inch apart. Refill pastry bag as needed with remaining dough.
Bake cookies until golden brown on bottom, about 12 minutes. Let cool on sheets on wire racks, and sprinkle with confectioners' sugar.