Preheat oven to 350°F. Line a muffin pan with paper liners.
Stir together muffin ingredients in a large bowl until combined. Scoop batter into paper liners until ¾ full.
Bake for 25 minutes or until a toothpick comes out clean. Let cool on a cooling rack.
Caramel Icing
Melt butter in small saucepan over medium low heat. Stir in brown sugar and milk and bring to a boil. Remove from heat. Cool slightly. Whisk in powdered sugar.
Place icing in a small baggie and cut out corner. Drizzle icing over muffins.