Banana chocolate chip muffins - chinese grandma

Ingredients

• 1 3/4 cups flour
• 3/4 cup sugar (1/2 cup is enough if you have very ripe bananas)
• 1 teaspoon baking powder
• 1 teaspoon baking soda
• 1/4 teaspoon salt
• 1/2 cup butter (1 stick), melted (FLAXSEED VARIATION – substitute 3/4 cup flaxseed meal for 1/4 cup of the butter)
• 1 egg
• 1/2 cup plain yogurt
• 1 teaspoon vanilla extract
• 1 cup mashed banana (~3 bananas)
• 3/4 cup semisweet chocolate chips