Macaroni and Cheese with Caramelized Onions and Bacon

INGREDIENTS

• 1 (16 ounce) package elbow macaroni
• 1/4 cup butter
• 1/2 cup sour cream
• 1 egg, beaten
• 2 tablespoons cream cheese, softened
• 4 cups grated Asiago cheese
• 4 cups grated Vermont Cheddar cheese
• 4 slices bacon
• 2 tablespoons butter
• 1 large onion, sliced thin
• 4 cloves garlic, minced
• 1/8 teaspoon brown sugar
• 1/4 cup chopped fresh parsley
• 1/4 cup panko bread crumbs
• 5 tablespoons all-purpose flour
• 3 cups milk
• 1/2 teaspoon ground mustard
• 1/2 teaspoon paprika
• 1/4 teaspoon salt
• 1/2 teaspoon pepper
• 1 tablespoon hot pepper sauce