In a small bowl, beat the cream cheese, sugar and zest until blended; set aside. In another small bowl, cream butter and brown sugar until light and fluffy. Add the eggs, milk and orange juice; mix well. Combine the flour, baking powder, baking soda and cinnamon; stir into creamed mixture just until moistened. Stir in the carrots, raisins and walnuts.
Fill greased muffin cups with 2 tablespoons batter. Top each with 2 teaspoons filling; top with remaining batter. Bake at 350° for 23-25 minutes or until a toothpick inserted near the comes out clean. Cool for 5 minutes before removing from pan to a wire rack to cool. Store in the refrigerator.