For the crust
For the filling
1. Preheat oven to 350 F. In a medium bowl, combine the flour and powdered sugar. Using a pastry blender cut in butter until the mixture resembles coarse crumbs.
2. Pat the crumbs into a well greased 9 x 13 in baking pan. Bake the crust at 350 F for 10-12 min or until lightly browned.
3. While the crust is in the oven, mix together eggs, sugar, flour and salt.
4. Gently stir in the diced rhubarb. Pour the rhubarb mixture over the hot crust. Return bars to the hot oven. Reduce oven temperature to 325 F and bake for 30-35 min or until the filling is set.
5. Cool and cut into bars.