Cream butter and sugar. Beat in eggs and vanilla; stir in carrots, apples, raisins and nuts.
Sift together flour, soda and salt; stir into creamed mixture. Add crumbs and mix well.
Spoon into well-oiled 1½-qt. mold. Cover securely with mold lid or several thicknesses of waxed paper tied in place with string.
Place mold on a rack in covered kettle of boiling water. (Water should come halfway up on the mold.) Steam for 3 hours. Unmold pudding onto serving plate; flame if you wish (directions follow). Serve hot with warm Caramel Sauce.