Preheat your oven to 350°F (175°C) and prepare a 9x13-inch baking pan with parchment paper or grease it with butter.

In a mixing bowl, combine 2 cups of all-purpose flour, 0.5 cup of granulated sugar, and a pinch of salt. Cut in 1 cup of softened cold butter until the mixture resembles coarse crumbs.

Pack the crumb mixture into the prepared pan and bake for 15-20 minutes until lightly golden.

In a clean bowl, whisk together the eggs and then mix in 2 cups of sugar, 0.5 cup of flour, and 0.5 teaspoon of baking powder. Fold in diced rhubarb.

Pour the filling over the cooled crust and spread evenly.

Bake for an additional 40-45 minutes until the filling is set and golden on top.

Let the bars cool completely in the pan before slicing into squares.