In a large mixing bowl, combine the cake mix, pudding mix and cinnamon. Whisk the eggs, orange juice and oil; add to dry ingredients. Beat until well blended. Stir in the carrots, raisins and nuts (batter will be thick).
Pour into two greased and floured 9-in. round baking pans. Bake at 350° for 30-35 minutes or until a toothpick inserted near the center comes out clean. Cool for 10 minutes before removing from pans to wire racks to cool completely.
For frosting, in a small mixing bowl, beat cream cheese and butter until fluffy. Add the confectioners' sugar, orange juice and peel; beat until blended. Spread between layers and over top and sides of cake. Store in the refrigerator.