Chocolate Espresso Cupcakes

Ingredients

• 1 1/2 cup flour
• 1 cup sugar
• 1 teaspoon baking soda
• 1/2 cup cocoa powder
• 1 teaspoon espresso powder
• 1/4 teaspoon salt
• 1 cup milk
• 1 tablespoon vinegar
• 1 teaspoon vanilla
• 1 Large egg
• 3/4 cups semisweet chocolate chips