Sweet Potato and Apple Casserole

Bahan-bahan (6 porsi)

• 4 sweet potatoes (approx 2 ½ pounds, peeled and cut into 1-inch dice)
• 4 small apples (or 3 large, peeled, cored and diced into 1-inch pieces)
• ½ cup melted unsalted butter
• ½ cup dark brown sugar
• ¼ cup maple syrup
• 2 teaspoons pumpkin pie spice
• ¼ cup chopped pecans
• salt (to taste)