Step 1

Wash yams thoroughly and poke on all sides with a fork to allow steam to escape while cooking.

Step 2

Arrange yams in a spoke pattern on several layers of paper towel in the microwave.

Step 3

Cook on the "baked potato" setting or until yams are soft all the way through when poked with a fork.

Step 4

Remove from microwave oven and allow to sit and cool for 10 minutes or until they are cool enough to handle.

Step 5

Slice yams in half lengthwise and scoop out cooked contents with a spoon. Discard skins.

Step 6

In a bowl, combine yams, butter, maple syrup, vanilla extract, 1/4 cup of brown sugar, and heavy cream. Mix well, mashing with a fork or potato masher until most lumps are smooth.

Step 7

Spread yam mixture into a 9x13 glass baking dish or similar casserole dish.

Step 8

Sprinkle mini marshmallows evenly over the yams.

Step 9

Bake at 375 degrees for 20-25 minutes or until the marshmallows are toasted brown. Remove from oven and serve immediately.