Preheat oven to 325 degrees F and line a 9x 13-inch baking pan with parchment paper. Leave a little hanging over the sides to make it easier to cut and remove the bars.
Mix the crust. Cream butter and sugar together in a medium bowl. Add salt and vanilla extract, then add in flour and stir until completely mixed. The dough will be thick and slightly crumbly. Press the dough firmly into the baking pan, making sure it’s even. I like to use my fingertips to press it in (don’t forget the corners). Bake for 15 minutes - you want the edges to be lightly brown.
Prepare the filling. Sift together the sugar and flour in a large bowl. Add eggs, Campari, grapefruit juice and zest. Whisk until fully combined.
Pour the filling over the warm crust and spread out evenly. Bake for about 35 minutes or until the filling hardly moves when gently shaken and the center is slightly set.
Cool. Remove from the oven and let cool at room temperature for about 2 hours. Then transfer to the fridge until it’s completely chilled.
Cut and enjoy! Once completely cooled, lift the parchment paper out of the baking pan and set on a cutting board. Dust with powdered sugar and cut into squares. Enjoy!
Notes
PREP AHEAD: You can prepare the curd and the shortbread crust in advance and simply bake them together for a dessert that comes together in about 35 minutes. If you make them in advance, wait to dust them with powdered sugar until just before serving. LEFTOVERS/STORAGE: These bars can be refrigerated for up to a week, you may need to re-dust them with powdered sugar. They can also be frozen individually for 3-4 months and thawed in the fridge. NUTRITION NOTES: These Grapefruit Campari Bars are an indulgent dessert. While it is fruit based, it’s made with shortbread crust and the filling is sweetened, which contributes fat and added sugar. That’s not to say these Grapefruit Campari Bars can’t be part of a balanced diet, just be mindful of portion sizes.Adapted from CookingLight.com.