Gather all of your ingredients.
Prepare the chopped Onion (1 cup) and chopped Bell Pepper (1 cup) by first cutting them into big chunks.
Take the chunks of veggies and place them in an electric chopper.
Add the veggies, the Canned Diced Tomatoes (14.5 ounce), Water (1 cup) and Marinara Sauce (26 ounce) to the slow cooker.
Add the Wagon Wheel Pasta (1 cup).
Toss in the Turkey Pepperoni (4 ounce).
Season with Italian Seasoning (1 tablespoon).
Stir everything together.
Cover the slow cooker. Cook the pasta mixture for 3-4 hours. Timing may vary depending on the slow cooker.
Sprinkle your dish with a little Shredded Mozzarella Cheese (1 1/2 cup) and enjoy!