Preheat the oven to gas 4, 180°C, fan 160°C.
Mix together the flour, sugar and baking powder in a large mixing bowl. Slowly mix in the olive oil and sparkling wine. If the dough is too dry, add another tablespoon of the wine. However, this dough should be a little dry since the cookies are best slightly flakey. Add the lemon, if using.
Break off pieces of the dough and work with your hands until the dough is workable and not too dry. Roll the pieces of dough into ropes that are roughly 6 inches long and 1/2 an inch thick. Form a circle, overlapping the ends of the rope slightly.
Place the ciambelle on a cookie sheet lined with parchment paper and sprinkle with sugar.
Bake in the centre of the oven for 15 to 20 minutes, until golden brown. Cool on a rack.
We topped ours with chopped almonds, but you could decorate with a prosecco glaze, or leave plain.