Preheat the oven to 350°F / 180°C. Line a 12-hole muffin pan with paper liners.

Add the cold butter, powdered sugar, flour, and salt to a food processor. Pulse until the mixture forms fine crumbs, then continue blending until the dough begins to clump together around the sides of the bowl. When pressed between your fingers, it should hold together easily.

Alternatively, cut the butter into the flour mixture with a pastry cutter or two knives until it resembles fine crumbs, then work it briefly with your hands until it just starts to clump. You can also use a stand mixer fitted with a paddle attachment on low speed.

Scoop one tablespoon of dough into each muffin liner and press it firmly into an even layer using the back of a wooden spoon or the base of a small glass.

Spoon one teaspoon of lemon curd into the center of each base. Keep the curd away from the edges so it doesn't spill over during baking.

Crumble about 3/4 tablespoon of dough over the top of each filled cookie, breaking it into irregular pieces.

This recipe makes 14-16 cookies in total, so you will have dough left for a second batch.

Bake for approximately 20 minutes, until the edges and crumble topping are lightly golden.

Remove from the oven and leave the cookies to cool completely in their liners on a wire rack before removing. The filling sets further as they cool.

Before baking the second batch, allow the muffin pan to cool completely so the dough doesn't start to melt before going into the oven.