Slice sweet potatoes.
Drain peaches; reserve 1/2 cup syrup.
Drain apricots; reserve 1/2 cup syrup.
Alternate layers of potatoes and fruits in 1 1 /2-quart casserole, mixing in several marshmallows.
Blend brown sugar and reserved fruit syrups; pour over layers.
Top with remaining marshmallows; dot with butter.
Bake in 350-degree oven for 15 to 20 minutes or until golden brown.