Banana-Chocolate Chip Mini Doughnuts

INGREDIENTS

• 1/2 cup mini semisweet chocolate chips
• 1/2 teaspoon salt
• 2 large eggs
• 1/2 cup packed light brown sugar
• 1 teaspoon vanilla extract
• Cooking spray
• 1 1/2 cups whole-wheat pastry flour
• 1/2 cup vegetable oil
• 1/3 cup granulated sugar
• 1 cup mashed ripe bananas (2 to 3 bananas)
• 3/4 teaspoon ground cinnamon
• 1/2 teaspoon baking soda
• 1 teaspoon baking powder
• 1/2 cup low-fat plain yogurt
• 1 stick unsalted butter, melted