fondant knit mold; small rolling pin; mitten cookie cutter; decorator's paintbrush
Knead the food coloring and vanilla into the fondant until thoroughly combined and no streaks remain. Put the fondant in a re-sealable plastic bag.
Dust a small amount of cornstarch on a work surface. Roll out a piece of fondant to about 1/8-inch-thick and roughly the size of the knit mold. Place the rolled fondant on top of the knit mold and press down slightly to smooth out over the mold. Roll the fondant out with a small rolling pin, beginning in the center and rolling outwards, and then beginning in the center and rolling inwards so that the entire piece of fondant has been pressed into the mold evenly.
Flip the fondant over and gently peel back the knit mold to reveal the imprinted side of the fondant. Cut out the fondant using a mitten cookie cutter. Brush the back of the fondant with a light coating of water, adhere the fondant knit piece on to the cookie by pressing down slightly. Repeat until all the cookies are covered.
Brush the bottom edge of the mitten cookie with a generous amount of piping gel, about 1/4-inch-thick. Dip the edge of the cookie in the silver sprinkles to coat. Dust the tops of the cookies with edible silver luster dust.