Preheat your oven to 425°F (220°C).
Spread the frozen French fries in a single layer on a baking sheet.
Bake the fries in the preheated oven for about 20-25 minutes, or until they are golden and crispy.
While the fries are baking, warm the marinara sauce in a small saucepan over medium heat.
Once the fries are done, remove them from the oven and reduce the oven temperature to 375°F (190°C).
Top the fries with the marinara sauce, shredded mozzarella cheese, sliced pepperoni, chopped green bell pepper, and sliced black olives.
Return the loaded fries to the oven and bake for an additional 5-10 minutes, or until the cheese is melted and bubbly.
Remove from the oven and garnish with chopped fresh basil if desired. Serve immediately.