Combine ingredients. Use enough water to make a paste that can be piped through a piping bag. Let rest for at least 10 minutes in refrigerator. For gluten-free flours, you will need more water than you would for gluten flours. So if it feels like you're adding a lot of water, don't worry. Use enough for it to hold together without excess dripping water. This will be a soft dough.
Add the dough to a piping bag with a star shape decorative tip for Viennese whirls. Make a round loop (like a wreath or rosette).
Bake on 325°F/165°C for 12 minutes or until bottom edges are golden brown. For a more even bake or more crunchy cookie: flip cookies over and then bake tops for another 2 minutes.
Let cool, and take 2 cookies to make a top and bottom sandwich and then fill middle with jam or add a dollop gem of jam on the top.