Banana Nut Muffins

Bahan-bahan (15 porsi)

• 4 bananas (overripe, peeled, divided)
• 2 cups all-purpose flour
• 3/4 cup mentega tawar (dilelehkan dan didinginkan)
• 2 telur
• 1 cup gula
• 1 1/2 teaspoons soda kue
• 1/2 teaspoon garam
• 1 teaspoon pure vanilla extract
• 2 tablespoons sour cream (or yogurt)
• 1/2 cup kenari cincang