Preheat the oven to 160°C fan-assisted convection and grease two 12-hole mini muffin tins with non-stick spray.

Cream the butter, sugar (sachet 1) and lemon zest for 1 minute using an electric hand mixer until pale and fluffy, then beat in the egg yolk until combined.

Add the cookie mix (sachet 2) and mix until evenly combined but still crumbly. Weigh out 135g of the mixture in a separate bowl and set aside, then press the rest of the mixture together into a smooth dough.

Divide the dough into 14 even pieces and roll into balls. Drop a ball into each mini muffin cup and bake for about 12 minutes until just cooked through and starting to turn golden – if you only have one muffin tray, you will need to bake the remaining two cookie cups in a second batch.

Remove the trays from the oven and immediately press the cookie dough into a tart shell shape using the base of a small glass or the back of a small measuring spoon.

Fill each cookie cup with a teaspoon of jam, then divide the crumble mixture evenly on top of each cookie cup. Return the cookie cups to the oven and bake for about 10 minutes or until the crumble topping is golden and crisp.

Allow the cookie cups to cool in the tin for 10 minutes before removing, then dust with icing sugar to serve.

Tip: We suggest using a tart jam for this recipe over a sweet one to balance out the sweetness of the cookie dough. Lemon curd will also be delicious!