01 -
Preheat the oven to 400°F and line a baking sheet with parchment paper.
02 -
In a large bowl, whisk together the egg, breadcrumbs, Parmesan, Italian seasoning, minced onion, garlic powder, salt, pepper, and water until evenly combined. Add ground beef and ground turkey, mixing gently with clean hands until just combined.
03 -
On a clean surface, divide the mixture into 15 equal portions. Wet or spray your hands lightly with cooking spray and roll each portion into a ball. Place balls on the prepared baking sheet.
04 -
Bake meatballs for 15 to 20 minutes until fully cooked through.
05 -
About 5 minutes before meatballs are done, pour pasta sauce into a medium saucepan, cover, and heat over medium-low until warm. Reduce heat to low if it starts to bubble. Stir occasionally.
06 -
Once baked, combine meatballs with warmed pasta sauce. Allocate approximately ¼ cup sauce per every 3 meatballs, as per individual sandwich servings.
07 -
Move an oven rack to the top position and switch oven to broil. Remove parchment paper and replace with aluminum foil on the baking sheet. Arrange open buns on the sheet, place 3 meatballs with sauce in each bun, and top with 2 tablespoons shredded Mozzarella. Broil for about 2 minutes until cheese melts and buns toast lightly, watching carefully to prevent burning.