Heat skillet to medium heat and fry pepperoni for a few minutes until it becomes crisp. Remove from pan and place on paper towel to drain.
Heat 2 tbsp olive oil in skillet on low-medium heat.
Spread a thin layer of pizza or pasta sauce on tortilla.
Add a thin layer of cheese to the tortilla.
Add pepperoni and any other toppings.
Top with another thin layer of cheese.
Cover with another tortilla, and place in pre-heated skillet for about 3-4 minutes, until the cheese melts.
Carefully flip quesadilla over to cook the other side.
Remove from heat and cut into triangles - serve with extra pizza sauce. Enjoy!