One question that is often asked before preparing a sweet potato casserole is: do you top it with marshmallows or a sweet pecan crust? The first recipe for marshmallow-topped sweet potato casserole was actually published by a marshmallow manufacturer in 1917. So, was this cloyingly sweet concoction a clever marketing ploy or was it the pillowy topping to take an old holiday treat to new heights? The sweet potato casserole with pecans recipe originated in the South, and early variations of the recipe included different ingredients like cream or milk.

Source: Ruth’s Chris