Mix all the ingredients for the dough and work the dough until it becomes uniform (using a mixer or not).Cover it with plastic wrap while preparing the stuffing.Boil the spinach and squeeze it to eliminate the water.Cut it with a sharp knife to facilitate.Mix it with the ricotta cheese.Add the egg.Add the grated cheese, salt and pepper.Amalgamate all ingredients.Preheat the oven to 180°C/356°F.Divide the dough in two.Create 2 circles of 30cm/11.8in each using a rolling pin.Place the 1st dough circle on baking paper.Spread some breadcrumbs on it.Place part of the stuffing in the center of the circle and the remaining creating another circle around, as seen on the photos.Cover it with the 2nd circle of dough.Wet the borders and attach one to another using a fork.Place a small bowl over the central stuffing and punch with a fork all around.Using a sharp knife cut the borders in 3cm/1.2in slices.Turn them upside 90°.Bake for 30 minutes in preheated oven at 180°C/356°F.