Stacy's Half Cup Sweet Potato Casserole

Preheat an oven to 350 degrees F (175 degrees C).

Mix the flour, brown sugar, oats, and cinnamon together in a bowl; cut the butter into the mixture until crumbled.

Combine the yams and cranberries in a larger bowl. Stir 1 cup of the flour mixture into the yams and cranberries; pour the mixture into the bottom of an 8-inch square baking dish and top with the remaining flour mixture.

Bake in the preheated oven for 25 minutes; top with the marshmallows and return to the oven until the marshmallows are browned, about 10 minutes more.