Sour Cream Coffee Cake Muffins (Bakery Style)

Ingredients

• all-purpose flour
• granulated sugar
• cinnamon
• salt
• unsalted butter, melted
• vanilla extract
• baking powder
• baking soda
• milk, at room temperature
• sour cream, at room temperature
• unsalted butter, melted and slightly cooled
• large egg , lightly beaten
• light brown sugar
• powdered sugar
• milk