Cinnamon Swirl French Toast Casserole

Ingredients (7)

• + 1 stick butter, or as needed add to pantry
• + 1 (16 ounce) loaf cinnamon swirl bread (such as Pepperidge Farm®) add to pantry
• + 1 ½ cups milk add to pantry
• ✓ ¼ cup white sugar
• ✓ 4 eggs
• + 1 teaspoon vanilla extract add to pantry
• ✓ teaspoon salt