Pumpkin Milkshake

Bahan-bahan (2 porsi)

• 1/2 cup pumpkin puree (not pumpkin pie filling)
• 1/4 cup nonfat milk
• 1/2 medium ripe banana (cut into chunks and frozen (about 1/3 cup))
• 1 1/2 cups vanilla frozen yogurt (slightly softened)
• 1 teaspoon pumpkin pie spice (or 1/2 teaspoon cinnamon, plus a pinch each of ginger, nutmeg, and cloves)
• 1/4 teaspoon ground cinnamon
• 1 full sheet graham cracker (plus additional for topping)
• Whipped cream (optional for topping)