This is not instaNT, BUT IT MAY HELP:BUTTERSCOTCH PUDDING MIX
-----BASIC MIX-----
2 c Instant nonfat dry milk
5 c Brown sugar, firmly packed
3 c Cornstarch
1 t Salt
-----TO USE-----
2 c Milk
4 tb Butter
1/2 c Basic mix

Mix all the ingredients until they are well blended.
Store mix in an airtight cannister or tightly covered jar.

TO USE: Stir the mix in the cannister before measurin out 1/2 c mix into a saucepan. Add 2 c milk and 4 tb butter and cook over low heat, stirring, until mixture thickens and comes to a boil. Continue stirring for 1 minute, remove from heat, and pour into individual serivng dishes. Pudding will thicken further as it cools

Source: Cheaper and Better alternatives to storebought goods by Nancy Birnes