In the bowl of a stand mixer, dissolve the yeast in the water. Let it sit for a few minutes until it foams. Add in the oil, sugar and salt. Mix in 1 cup of the flour and mix until smooth. Gradually add in the rest of the flour. Change to the dough hook and mix until the dough is smooth. Continue to knead for about 5 minutes, until elastic.
Pour the olive oil into a large bowl. Add the dough then flip over to cover in oil. Cover the bowl and let it rise in a warm area until almost doubled, about 40 minutes.
In a medium skillet, cook the sausage until browned and cooked through. Remove to a plate, and add the mushrooms to the same skillet. Cook until soft.
In a bowl, combine the ricotta, cheese, pepperoni. Add in the cooked sausage and mushrooms. Stir in the basil leaves. Mix well and refrigerate until the dough is done rising.
Preheat the oven to 375F. Punch down the dough and separate it into 4 equal pieces. Roll each piece into a circle on a lightly floured surface. Fill each circle with ¼ of the filling mixture. Fold over the top of the dough, then fold over the edges, pinching to seal. Brush the top of each calzone with the egg, then place on a lightly greased baking sheet.
Bake for 30 minutes, or until golden brown. Serve with the marinara.
