Grandma B’s Rhubarb Custard Pie

2-1/2 cups rhubarb, cut into ¼ “ pieces and scalded
1 cup white sugar
2 tablespoons flour
2 eggs
1 tablespoon melted butter

Mix sugar with slightly beaten egg yolks. Stir in flour and rhubarb. Blend well. Add melted butter. Place in pastry, sprinkle topping on and bake at 425 degrees for 10 minutes. Lower to 325 degrees for 30 minutes.

Topping:
½ cup margarine
½ cup brown sugar
1 cup flour
Mix well until crumbly.