Blend all crust ingredents well in food processor or bowl. Pat into bottom of ungreased 9" x 12" baking pan, forming 1/2" sides.
Spread with rhubarb. Sprinkle dry Jello over rhubarb. (You may use a mixture of rhubarb and strawberries.)
Blend all topping ingredients in food processor or bowl. Sprinkle over rhubarb mixture. Bake at 350 for 40 minutes. Serve warm with vanilla ice cream if desired.