1-Preparing Your Workspace: First, preheat your oven to 350°F and lightly grease or line an 11×7-inch baking dish with parchment paper. The parchment paper will make it much easier to remove the bars after they’ve cooled, ensuring clean edges and neat squares when you cut them.

2-Making the Crust: In a medium bowl, combine 1 cup all-purpose flour, 1/4 cup powdered sugar, and 1/4 teaspoon salt. Add the 1/2 cup of room temperature butter, cut into pieces. Mix these ingredients together until the mixture resembles fine crumbs that clump together when pressed. This shortbread-style dough doesn’t need to be overly worked just mix until it comes together. Press the crumbly mixture evenly into your prepared baking dish. Use the back of a measuring cup or your fingers to create a uniform layer. Bake the crust for 18 to 20 minutes until it’s lightly golden. Keep an eye on it to prevent over-browning.

3-Creating the Grapefruit Filling: While the crust bakes, prepare your filling. In a medium bowl, whisk together 1 1/2 cups granulated sugar and 1/4 cup all-purpose flour until well combined. Add the 4 large eggs one at a time, whisking thoroughly after each addition to ensure a smooth texture. Stir in 1 tablespoon of grapefruit zest and 1 cup of grapefruit juice. If you prefer a more vibrant color, add a few drops of pink food coloring at this stage. The filling should be smooth and slightly thickened from the flour.

4-Baking and Cooling: Once the crust is golden, carefully pour the grapefruit filling over the hot crust. The heat from the crust will help create a nice seal between the layers. Return the dish to the oven and bake for 20 minutes or until the filling is set with slightly browned edges. The center should still have a slight jiggle when you gently shake the pan. Allow the bars to cool in the pan for about one hour. Then refrigerate them for 1 to 2 hours until completely cold. This chilling time is essential for the filling to set properly and for easier cutting. Once chilled, use the parchment paper to lift the bars out of the pan and cut into squares. For a beautiful finish, dust the top with powdered sugar just before serving. This not only adds sweetness but also creates an elegant, professional appearance.