The cake: Follow directions on box. Bake at 350 F for 12-18 minutes in a jelly roll pan or shallow pan at least 9x13 1/2".
The puddin': Prepare as directed on package except use 1 cup of milk and 1/2 teaspoon of vanilla. Let thicken.
The Roll-y Pole-y: Invert hot cake onto powdered sugar dusted towel laid on cooling rack. Roll up, towel and all. Let rest on loose side. Cool; un-roll, remove towel; spread on thickened pudding mix. Roll cake up. Dust with powdered sugar. Cut thick slices. Eat at once or keep refrigerated. Enjoy!