I have been making this recipe, for over 30 years for the Holiday's It's a tradition for us and a must for our Thanksgiving and Christmas Dinner. The first thing my family will ask me, when I walk in the door "Did you bring the Yams!
In Medium Bowl add flour, brown sugar, oaks, cinnamon. Mix all ingredients. Cut up butter in 1/2 inch cubes add to mixture and using a pastry blender or fork cut into dry ingredients until it resembles a crumb topping.
Wash cranberries, let drain and set aside.
Drain yams and put in a 2-quart casserole dish, add cranberries to yams in casserole dish, add 1 cup of crumb topping and toss lightly until yams and cranberries are coated with crumb mixture and cranberries are evenly distributed in dish.
Add the remaining crumb topping evenly on top of mixture in casserole dish.
Bake at 350 degrees for 40-50 minutes until bubbling and cranberries are completing cooked.
Remove from oven and Sprinkle 1-1/2 cups mini marshmallow on top cooked yams and return to oven and bake until marshmallows are lightly golden brown, watch carefully! you do not want to burn marshmallows.
Remove from Oven, let cool 5-minutes and Serve.
Note: Can be made the day before, after adding the remaining crumb topping. Cover with plastic wrap and put in refrigerator. Take out about 20 minutes before baking.