I never would have thought to put instant vanilla pudding mix in my oatmeal! (dineanddish.net)
Add the remaining buttermilk mixture and a packet of dry instant vanilla pudding and beat just until combined. (savorwithjennifer.com)
Instant vanilla pudding mix can be equally substituted for the pastry cream filling mix, though the flavor will not be quite as rich. (kingarthurflour.com)