Cut off stem ends and leaves of rhubarb and discard.
Wash well, drain and cut stalks into 1/2-inch lengths.
Mix sugar and rind, sprinkle over rhubarb and mix well.
Cut fig bars in small dice.
Put a layer of fig bar cubes, than a layer of rhubarb into a glass baking dish (6-cup).
Repeat until all are used, ending with a layer of fig bars on top.
Dot with butter and bake in a moderate oven (375° F.) for 20 minutes or until rhubarb is tender and until casserole is boiling hot all the way through.