Hi Charlotte,
While I was searching for the Jello Poke Cake recipe (as I had misplaced mine!), I came across a reply to your request for pudding cake. That recipe called for cooked type pudding. I have a different version that calls for INSTANT pudding. Perhaps you would like to try this one, too. Nadine from Nebraska

Jello Pudding Stripe-It-Rich Cake (Using INSTANT Pudding)

1 pkg. cake mix, any flavor
2 pkgs. (3 1/2 oz. ea.) Jello INSTANT pudding, any flavor
1 cup powdered sugar
4 cups cold milk

1. Prepare cake mix as directed on package, baking in a 9 x 13 pan. Remove from oven. Poke holes quickly down through cake with round handle of wooden spoon at 1-inch intervals (or use a plastic straw, using a turning motion to make large holes).

2. Only after poking holes, combine pudding mix with powdered sugar in large bowl. Gradually stir in milk. Then beat at low speed of electric mixer for not more than 1 minute (do not over beat). Quickly, before pudding thickens, pour about 1/2 of the thin pudding evenly over warm cake and into the holes to make the stripes.

3. Allow remaining pudding to thicken slightly; then spoon over the top, swirling it to "frost" the cake. Chill at least 1 hour. Store in refrigerator. Cover with plastic wrap if desired.

Happy Cooking!! :)