Beat butter and sugar with an electric mixer until light and fluffy. Add in egg and beat.
Slowly stir in the dry ingredients: ground almonds (or NADA Flour), gfJules Gluten Free All Purpose Flour, baking powder, cinnamon and salt. Mix until thoroughly incorporated.
Shape dough into a disc and wrap tightly with plastic wrap. Chill in the refrigerator for at least 2 hours, or until cold and no longer sticky.
Remove covered dough to come closer to room temperature before rolling.
Preheat oven to 375° F (static) or 350° F (convection).
Dust a baking mat or clean counter with plenty of gfJules Flour to keep the dough from sticking. Divide the dough in half and roll one half out while the other half remains wrapped.
Roll gently in different directions until the dough is uniformly 1/8 inch thick. Using Linzer cutters, cut out cookies with a center cutter to remove a shape from the center of half of the cookies. Roll out all the dough, cutting half the cookies with a Linzer cutter with the center cutter and half the cookies without the center cutter.
Lay cookies on parchment-lined baking sheets and bake for 6-7 minutes. They should still be soft but lightly browning around the edges. If you wait until the cookies are crunchy in the oven, they will be overcooked.
Remove to cool on wire racks; cookies will get slightly crunchier as they cool, then get softer if using jam instead of melted chocolate between them.
Melt the chocolate chips in a microwave-safe bowl or in a saucepan on the stove on medium-low, stirring constantly so it will not burn.
When completely melted, drizzle in a criss-cross pattern across the tops of the cut-out cookies or leave plain. Use a knife or offset spatula to spread a thin layer of chocolate on top of each full cookie, placing a cut-out cookie on top while the chocolate is still melted.
If you would like to also use raspberry jam, spoon a small amount into the center of the cut-outs, on top of the melted chocolate. Drizzle more chocolate on top, if desired.
Dust with confectioner’s sugar before serving.