Cream crust ingredients until pebbly and pat into 9x13 pan
Cover with rhubarb mixture
Bake at 450º for 10-15 minutes, until crust edges are brown and caramelized
Remove from oven and drop temperature to 350º
Pour custard mixture over hot rhubarb
Place back in oven and bake at 350º for 20-25 minutes, until custard barely wiggles when shaken
Notes
All measurements are estimates. Use as much fruit as possible, and if the crust does not fill the 9x13 pan, add a little more butter, a little more flour, etc. until it does.