Preheat oven to 375°F. Dust work surface with cornmeal or flour.
Roll dough into desired size, ensuring enough space to fold over the fillings.
Drizzle dough with olive oil and line with provolone slices. Sprinkle garlic powder, onion powder, and oregano over it.
Add ham, pepperoni, mozzarella, and top with salami. Fold long sides over and seal ends. Place seam-side down on parchment-lined sheet.
Whisk 1 egg with 1 tbsp water, brush egg wash over stromboli. Optionally, sprinkle parmesan and basil on top.
Bake for 40 minutes until golden brown. Let rest 10 minutes before slicing. Serve with marinara sauce for dipping.