Coffee custard tart

To make the base, beat together the sugar and butter using an electric whisk until light and fluffy. Add the plain flour, cornflour and a pinch of salt, then bring together into a dough using your hands, adding 1 tsp of cold water at a time until smooth. Wrap and chill for at least 1 hour.

Heat the oven to 200C/fan 180C/gas 6. Roll the pastry out on a lightly floured worksurface, then use it to line a 28cm loosebottomed tart tin. Trim the edges, line the tart with baking paper, then tip in some baking beads and bake for 15 minutes. Remove the beads and paper, pierce the pastry with a fork and turn down the oven to 180C/fan 160C/gas 4. Bake for 10 minutes more, then turn down the oven again to 120C/fan 100C/gas 1. Whisk the egg yolk, brush it over the base, and bake the case for another 5 minutes.

Mix together all of the coffee custard ingredients, then carefully pour into the tart case. Bake for 45 minutes-1 hour or until just set with a slight wobble in the middle. Remove from the oven and leave to cool.

To make the crumble, melt the chocolate and butter in a heatproof bowl in the microwave in short bursts. Combine the dry ingredients in a separate bowl. Mix the wet into the dry, then chill for 1 hour. Heat the oven to 200C/fan 180C/gas 6. Spread the crumble mixture over a baking tray and bake for 10 minutes. Remove from the oven, break up roughly with a fork and bake for another 10 minutes. Remove from the oven and leave to cool.

Top the cooled tart with the coffee crumble, then cut into slices to serve.