Add minced garlic to melted butter. Let sit for a few minutes for flavors to combine.
Remove mushroom stems and wash any dirt from mushroom caps.
Place foil on a baking sheet and spray with cooking spray.
Brush both sides of mushrooms caps with garlic butter and place on prepared baking sheet stem side up.
Place a slice of provolone into each cap folding cheese in on itself so it stays inside the cap. Add mozzarella, sun-dried tomatoes, and pine nuts into mushroom cap.
Place baking sheet in preheated oven and bake for 15 minutes.
While mushrooms bake, pour balsamic vinegar into a small saucepan and cook over a low heat until vinegar is reduced by half.
Check mushroom caps, the mushrooms should be soft and the cheese melted. Depending on the size of the mushrooms they may need to cook for another 5-10 minutes.
Remove mushrooms from oven and drizzle with reduced balsamic vinegar. To serve, garnish with basil and crushed red pepper.