Pre-heat your oven to 350 degrees.
Clean the mushrooms and remove the stem. Place them bottom side up on a baking dish and drizzle them with 2 tablespoons of olive oil. Put 2 teaspoons of pizza sauce and pesto into each cavity.
Add 2-3 mozzarella balls on top of each mushrooms along with a sprinkle of sun-dried tomatoes.
Transfer the baking dish to the oven and bake for about 20-25 minutes until the mushrooms are tender and then cheese is melted.
Remove the baking sheet from the oven and top with the freshly cut basil and serve immediately.