I see no reason why you cannot do this in a bundt pan. Just allow more baking time, I'd guess 35 to 40 minutes total.
Marilyn Amazing Orange Pineapple Cake and Frosting Makes a 9 by 13 cake Drain and reserve juices separately: 11 ounce can mandarin oranges 20 ounce can crushed pineapple Cake Mix well: 1 box Duncan Hines Cake Mix (pudding in mix) 1/2 cup vegetable oil 4 eggs 2/3 cup reserved mandarin orange juice Fold in drained oranges. Bake at 325 degrees, 25 minutes. Let cool in pan. When cooled, poke a few small holes in cake and drizzle with minimal amount of reserved pineapple juice. Frosting Mix together: 1 large box Instant vanilla pudding dry mix drained pineapple Add: 1 large tub Cool Whip Frost Cake and chill overnight.