Grandma always made this 3 ingredient masterpiece when unexpected guests arrived. It sets up perfectly in the fridge and everyone begs for her secret.
Sprinkle the instant butterscotch pudding mix over the milk. Let it sit for just a few seconds so the powder starts to absorb the milk instead of puffing everywhere.
Using a whisk or a hand mixer on low speed, beat the pudding and milk together for 2 minutes, or until the mixture is smooth, thick, and glossy. It should be noticeably thicker than when you started and just beginning to mound on the whisk.