Giada De Laurentiis' baked pesto pasta casserole

Ingredients

• 1 pound penne rigate
• 1/4 teaspoon salt
• 1/8 teaspoon freshly ground black pepper
• 2 tablespoons olive oil
• 2 shallots, minced
• 3/4 pound dark meat turkey
• 1 cup purchased basil pesto
• 1 cup freshly grated Parmesan cheese
• 2 cups store bought marinara sauce
• 1 tablespoons unsalted butter, cut into 1/4-inch pieces