Roll the room-temperature dough out into a large rectangle Spread the pizza sauce on top of the dough, leaving a 2-inch border around the perimeter.
Sprinkle shredded mozzarella evenly over the top. Next, add the sliced salami, ham, and pepperoni. Brush the edges of the dough with the beaten egg. Then, roll up the dough like a jelly roll. Pinch the edges together and tuck under.
Brush the top of the dough with the egg wash. Next, sprinkle with freshly grated parmesan cheese, and then evenly sprinkle the garlic powder over the top.
Gently make shallow diagonal cuts into the top every 2 inches. Bake the stromboli at 375 for 25-30 minutes, until the top is golden brown.