A sweet church friend handed down this secret method using just 4 basic pantry staples poured directly in.

For a slightly lighter texture, you can swap 1/2 cup of the whole milk for 1/2 cup of half-and-half or evaporated milk, which gives a richer sauce without making the sponge too heavy. If you like a deeper caramel flavor, stir 1 teaspoon of vanilla extract into the milk before pouring it over the dry mixes.

(This technically adds a fifth ingredient, so consider it optional if you’re sticking to the four-staple method). For a nutty twist, sprinkle 1/2 cup chopped pecans or walnuts over the top along with the butterscotch chips before cooking; they’ll toast gently and add a little crunch. If your slow cooker runs hot, check the cake 15–20 minutes earlier the first time you make it so the edges don’t overcook—this dessert is meant to be soft and spoonable, not dry.

Leftovers reheat nicely in the microwave in short bursts, and if the sauce thickens too much, you can splash in a tablespoon of milk when reheating to loosen it back into a pourable butterscotch puddle.