Instructions

Make the cookie dough:

1. Blitz the black sesame seeds in a food processor or blender until you get a rough, mealy texture.
2. Cream the softened butter, sugar, lemon zest and salt in a medium bowl until smooth (you could use a stand mixer with the paddle attachment fitted instead).
3. Add the ground black sesame seeds, ground almonds and flour and mix until you get a crumbly dough. Add the egg yolk and mix until a cohesive dough forms.
4. Divide the dough into two balls, flatten into disks and place into separate re-usable sandwich bags. Chill for at least 1 hour until firm.

Make the ganache filling:

1. Finely chop the white chocolate and place into a heatproof bowl.
2. Place the creme fraiche, lemon zest and salt into a small pot. Set over a low heat and allow to loosen and warm up.
3. Once gently steaming, remove from the heat and pour over the white chocolate. Let it sit for 5 minutes to melt the chocolate and then stir together until smooth. Finally, stir in the lemon juice.
4. Allow to cool (either at room temperature if your kitchen is cool, or, in the fridge if not) until the texture is thick but you're still able to stir it.
5. Use an electric whisk to beat the cooled ganache until light and fluffy.

Cut and bake the cookies:

1. Cut a large piece of baking paper and place on your work surface. Dust with plain flour.
2. Remove a chilled disk of dough from the fridge, take out of the bag and place onto the baking paper and dust with more plain flour.
3. Roll the dough out until it's about 2mm (1/16-inch) thick, dusting the top and underneath the dough with flour as needed to prevent it sticking to the paper too much. Cut out into 5cm (2-inch) circles. Remove the scraps around the edges and transfer the circles to a baking tray lined with baking paper. Chill for 15 minutes.
4. As the cut cookie dough is chilling, preheat the oven to 130°C (266°F). Use this time to also roll and cut circles from the second disc of dough. Place onto a second, lined baking tray. Use a small circular cutter (or the end of a piping tip) to cut a small circle from the centre of these cookies. Chill for 15 minutes as well.
5. Remove the chilled cookie circles from the fridge and bake for 25-35 minutes; the cookies should barely start to colour and should become crisp once cool (they'll stil lbe slightly pliable when hot). Allow to cool on a wire rack.
6. Re-roll the scraps, cut and bake as above, making sure that there's one plain circle per one 'doughnut shaped' circle so they can pair up when being sandwiched!
7. Take a plain circle cookie (without the hole) and spread a thin layer of the white chocolate ganache over the surface of the cookie. Take one of the cookies with the hole in the middle and sandwich it on top. Repeat with all your baked cookies!
8. Store in an airtight container for up to 5 days - they will soften a bit as they sit.