In a large mixing bowl, combine warm water, sugar, and instant yeast. Let sit for 5 minutes until foamy. Mix in olive oil, flour, and salt. Knead for 5-7 minutes until smooth, then cover and let rise for 1 hour.

While dough is rising, cook ground beef and Italian sausage in a skillet over medium heat until browned. Drain fat and add onion and bell pepper; cook for 3-4 minutes. Stir in Italian seasoning and garlic powder, then add pizza sauce and let cool.

Preheat oven to 375°F (190°C). Roll out half the dough and place in greased pie pan. Layer with half the mozzarella and cheddar cheese, meat mixture, remaining pizza sauce, and more cheese. Add pepperoni slices if desired.

Roll out second half of dough for the top layer. Place over filling and seal edges. Cut slits in top crust for steam to escape. Brush with egg wash.

Bake assembled pie in the preheated oven for 35-45 minutes until golden brown. Cover with foil if browning too quickly.

Allow pie to rest for 10 minutes before slicing. Garnish with parsley and serve warm with extra pizza sauce.