Preheat the oven to 400°F (200°C).
In a skillet, cook the sausage over medium heat until browned. Drain excess fat.
Add spinach to the skillet and cook until wilted, about 2-3 minutes.
Roll out the pizza dough into a large circle. Spread ricotta cheese on half of the dough, leaving an edge for sealing.
Top with cooked sausage, spinach, and mozzarella cheese.
Fold the dough over the filling and seal the edges by pressing with a fork.
Brush the top of the calzone with the beaten egg.
Bake in the preheated oven for 20-25 minutes, or until the crust is golden brown.
Allow to cool slightly before serving.