Cut the sub buns lengthwise and arrange cut side up on a large cookie sheet.
Divide the pizza sauce among the buns, spreading it over the surface of each slice.
Sprinkle the mozzarella cheese over top of the pizza sauce.
Arrange your choice of toppings on one side of your sandwich.
Once your pizzas are assembled, place them in the oven on the lower rack for about 8 to 10 minutes, or until the cheese is hot and bubbly. Match up the top of your sub bun with the bottom and cut in half to serve.
Tip: Taking your pizza subs to go? Wrap in Parchment paper or foil to keep warm.