Slice the zucchini in to ¼" inch rounds and place on a baking try that has been lined with either parchment paper or aluminum foil. If you use aluminum foil, make sure you spray it with non-stick cooking spray.
Brush the top side of each zucchini round with olive oil and season with salt and pepper.
Bake for 2 minutes and then flip each zucchini round and brush with a little more olive oil, season with salt and pepper. Return to the oven for an additional 1 to 2 minutes of baking.
Remove the tray from the oven and add a spoonful of marinara sauce on top of each zucchini round.
Divide the mozzarella cheese evenly to the zucchini rounds and then sprinkle with a little Parmesan cheese on top.
Turn the oven up to broil and place the baking tray under the broiler for 1 to 2 minutes or until the cheese is hot and bubbly.
Let cool slightly before serving.
Notes
Feel free to add your favorite pizza toppings such as pepperoni, mushrooms or chopped peppers.