Olive oil cooking spray
1 (9-inch) frozen piecrust, thawed for about 10 to 15 minutes
1 1/2 cups grated Parmesan cheese, divided
2 tablespoons butter
2 tablespoons olive oil
1 cup thinly sliced shallots
3/4 pound mixed wild mushrooms (such as chanterelles, hedgehogs and creminis), roughly chopped
Salt and pepper to taste
1/4 cup dry sherry or white wine
1/2 cup vegetable or low-sodium chicken broth
1/2 cup crème fraîche