Preheat oven to 350º F. Line rimmed baking sheet with parchment paper. Divide pizza dough in half and spread out on parchment paper. Set aside.
Add sausage to skillet over medium heat. Break apart with a wooden spoon and stir in onion, garlic, and all peppers. Cook until the sausage has browned and cooked throughout and the vegetables are tender. Remove from heat.
Spoon half of sausage mixture, draining off as much of the excess drippings as possible, on one dough and the remaining on the second dough. Add ham, pepperoni, cheeses, and spinach to the sausage mixture and then roll the dough into a cylinder. Bake for 15 minutes and remove from the oven. Mix melted butter and minced garlic together and brush on top of the stromboli.
Sprinkle with Parmesan cheese and return to the oven for 5-8 more minutes to brown. Remove from the oven and allow to cool for about 10 minutes. Then slice into thick slices and serve.