This is a favorite of my family and we would usualy fix it for dinner for dessert and serve it warm with milk.
You can substitute whole wheat or whole spelt flour. With whole wheat use approx 1/4 c. less. This recipe is also good with less sugar for those that want to cut back. Enjoy! -Sovilla
Grease bottom of 13x9x2 baking pan, sprinkle brown sugar evenly over it. Spread rhubarb on top of sugar.
Cream shortening and sugar, add egg yolks, and vanilla, mix well. Add dry ingredients, mix, then fold in stiffly beaten egg whites. Pour batter over rhubarb and bake in a moderate oven at 350F for 45 min.