Put all dry ingredients in a bowl and stir. Add the ricotta and knead everything into a smooth dough. If the dough is still too sticky, work in a little flour. Divide the dough into 12 portions. Roll balls with floured hands, press flat and place on a baking sheet lined with baking paper. Make a hole in the center of each sheet of dough with a floured wooden spoon handle.
Bake in the oven preheated to 160 ° C for about 15-20 minutes until they are lightly brown. Take out of the oven and dust the warm rings with icing sugar.