Place dough balls in tart pan and press with tart press or fingers to form to shape of tart pan.
Bake in oven for 10 minutes.
Make orange sugar by rubbing orange zest into sugar with fingers. It will become very fragrant.
Remove cookie cups from oven and press center of cup back down into pan using tart press (or use a wooden spoon handle if you don't have a tart press).
Place back in oven and bake another 5 minutes.
Remove from oven and cool on cooling rack for 10 minutes. Remove tarts from pan and place on cooling rack. Cool completely.
Pipe or spoon hazelnut spread into cooled cookie wells. About 1-1/2 tablespoons per cup.