4 1/2 pounds sweet potatoes
1/2 cup sugar
1/2 cup Splenda
1/2 cup milk
1/4 cup butter, softened
2 large eggs
1 teaspoon vanilla extract
1 tsp cinnamon
1 1/4 cups graham crackers, crushed
1 tablespoon brown sugar
1 tablespoon butter, melted
1 1/2 cups miniature marshmallows
Bake sweet potatoes at 400° for about 1 hour or until tender. Let cool to touch; peel and mash sweet potatoes.
Beat mashed sweet potatoes and next 7 ingredients at medium speed with an electric mixer until smooth. Spoon potato mixture into a greased 11- x 7-inch baking dish.
Combine graham crackers, brown sugar, and butter in a small bowl. Sprinkle diagonally over casserole in rows 2 inches apart.
Bake at 350° for 30 minutes. Remove from oven; let stand 10 minutes. Sprinkle alternate rows with marshmallows; bake 10 additional minutes. Let stand 10 minutes before serving.