Instructions

Step 1: Prepare the Crust

1. Preheat the oven to 350°F (175°C) and line a 9×9-inch baking pan with parchment paper.
2. In a mixing bowl, cream the butter and sugar together until light and fluffy.
3. Add the flour and salt, mixing until a soft dough forms.
4. Press the dough evenly into the prepared baking pan.
5. Bake for 18-20 minutes, or until the edges are lightly golden.
6. Remove from the oven and set aside to cool slightly.

Step 2: Prepare the Filling

1. In a medium bowl, whisk together the eggs and sugar until smooth.
2. Add the pink grapefruit juice, lemon juice, and zest, stirring to combine.
3. Sift in the flour, baking powder, and salt, and mix until fully incorporated.
4. If using food coloring, add a small drop and stir until the mixture reaches a light pink hue.
5. Pour the filling over the slightly cooled crust and spread evenly.