In a small mixing bowl, beat filling ingredients till well mixed. Set aside. In a large mixing bowl, make the cake mix: Combine eggs and sugar and beat till light. Add carrots and oil and beat till well combined. In another bowl, mix dry ingredients and add to carrot mixture. Stir in walnuts and raisins.
Grease and flour a 10 inch fluted tube pan. Place 3 cups of mix into pan and top with filling mixture. Place remaining batter on top of filling covering as much as possible. Bake 350° for 55-60 minutes. Cool for 15 minutes and remove from pan. Cool completely and sprinkle with powdered sugar. Refrigerate leftovers.