Bright and tangy orange bars with a buttery shortbread crust, a silky citrus filling, and an optional orange glaze. Simple ingredients, big flavor, and perfect for any occasion.
Preheat oven to 350°F. Line an 8x8 inch baking pan with parchment, leaving overhang, and lightly grease.
Make the crust: In a bowl, stir melted butter, 0.25 cup sugar, 1.5 cups flour, and 0.25 tsp salt until a soft dough forms. Press evenly into the pan.
Bake crust for 15 minutes until set and lightly golden at the edges.
Make the filling: Whisk 1 cup sugar with 0.25 cup flour. Whisk in eggs, 0.5 cup orange juice, 1 tbsp zest, vanilla, and 0.125 tsp salt until smooth.
Pour filling over the hot crust and return to the oven. Bake 18 to 20 minutes, until the center is set with a slight jiggle.
Cool in the pan on a rack for 60 minutes, then chill 30 minutes to firm. Lift out using parchment and cut into 16 bars.
Glaze (optional): Whisk powdered sugar with orange juice and 0.5 tsp zest until smooth. Drizzle over cooled bars and let set 10 minutes.
Notes
For clean cuts, wipe the knife between slices. Bars keep covered in the refrigerator for 4 days or freeze up to 2 months. Use freshly squeezed juice and finely grated zest for the brightest flavor.