Prep time: 20 minutes. Bake time: 25 minutes. Makes 12 muffins.
Heat oven to 375 degrees (F). Grease muffin cups or use paper baking cups.
In a medium bowl, combine flour, baking powder, cinnamon, and salt.
In bowl of electric mixer, mix eggs and brown sugar until smooth. Add milk and melted butter and continue mixing. Add flour mixture and blend well. Stir in carrots, raisins, and nuts.
Scoop batter into muffin cups and bake for 20 to 25 minutes. Let cool completely and frost with cream cheese frosting.
In bowl of electric mixer, beat butter and cream cheese until fluffy. Add the powdered sugar, one cup at a time, blending well. Add in the vanilla extract.
Beat until frosting has a light, fluffy texture, about 5 minutes.