Directions

1. Dissolve the sugar in the warm water in the bowl of a stand mixer fitted with a dough hook. Sprinkle the yeast over the water, and let stand for 5 minutes until the yeast softens and begins to form a creamy foam. Stir in the oil, salt, and 2 cups of flour, and mix on Low until the mixture forms a wet dough. With the machine running, add 1 cup of flour, 1/4 cup at a time, and knead until the dough pulls away from the sides of the bowl into a ball. Knead for 3 to 5 more minutes, until the dough is smooth and elastic.
2. Lightly oil a large bowl, then place the dough in the bowl and turn to coat with oil. Cover with a light cloth and let rise in a warm place (80 to 95 degrees F (27 to 35 degrees C)) until doubled in volume, about 1 hour.
3. Combine the ricotta, mozzarella, and Parmesan cheeses, pepperoni, parsley, Italian seasoning, olives, green pepper, and mushrooms in a large bowl, and set aside.
4. Preheat oven to 375 degrees F (190 degrees C). Line a baking sheet with parchment paper.
5. Punch down the dough, and roll it out into a long, flat strip about 9 inches wide by 30 inches long. Spoon the filling mixture down the center of the dough strip, leaving about 1 inch on all sides for sealing. Pull edges of the dough together; pinch to seal and form a long, filled roll. Place the roll, seam side down, onto the parchment paper in a snakey "S" shape, and tuck the ends underneath to seal. Beat the egg in a bowl with 1 tablespoon of water, and brush the egg wash over the calzone.
6. Bake in the preheated oven for 30 to 35 minutes, until the calzone is golden brown. Let cool for 5 minutes before cutting into individual slices.