In a mixing bowl, combine the crust ingredients: flour, powdered sugar, and cold butter. Mix until crumbly and press into the bottom of a greased baking dish.
Bake the crust for 15 minutes. While the crust bakes, prepare the filling.
In another bowl, whisk together the eggs, granulated sugar, flour, and salt. Fold in the diced rhubarb.
Pour the filling over the baked crust and return to the oven. Bake for an additional 25 minutes, or until the filling is set.
Let cool before cutting into bars and serving.
Notes
For a sweeter taste, adjust the sugar in the filling to your preference. You can also substitute the rhubarb with other fruits if desired.