Take a piece of store-bought fondant about the size of your hand, knead briefly, and roll out to 1/4-inch thickness on a surface dusted with confectioner's sugar. Move the fondant frequently when rolling so it doesn't stick to the counter, and use additional confectioner's sugar as needed to prevent sticking. Cut out circles using the same cookie cutter used for the cookies. Place the circles on a baking tray lined with wax or parchment paper. Cover the fondant circles with a piece of wax paper until ready to use.