01 - 
                Preheat oven to 350°F (175°C).
              
              
              
                02 - 
                In a medium bowl, combine flour and powdered sugar. Cut in the butter until the mixture resembles coarse crumbs.
              
              
              
                03 - 
                Press crust mixture evenly into a greased 9×13-inch baking dish.
              
              
              
                04 - 
                Bake the crust for 10 minutes and remove from the oven.
              
              
              
                05 - 
                In another bowl, whisk together the granulated sugar, flour, and salt. Add eggs and whisk until smooth.
              
              
              
                06 - 
                Stir in the diced rhubarb and pour the custard filling over the pre-baked crust.
              
              
              
                07 - 
                Bake for an additional 35–40 minutes, or until the custard is set and the edges are lightly golden.
              
              
              
                08 - 
                Let cool completely before slicing into bars. Dust with powdered sugar if desired.