Chocolate miso pan-bang cookies

Method

1. Beat the butter and sugar together until pale and fluffy – you can do this in a stand mixer with a paddle attachment for about 3 minutes or by hand for about 8 minutes. Beat in the egg, then sift and stir in the flour, bicarbonate of soda and salt. Stir in the miso, milk chocolate and half the sesame seeds.
2. Heat the oven to 160°C fan/gas 4. Tip the dough out onto a work surface and roll into a 3cm thick log. Slice the log into 10-12 discs and put 3 of them
   on a baking tray lined with baking paper, leaving plenty of room around each one. Sprinkle some of the remaining sesame seeds over the top of the discs, then chill the tray in the freezer for 15 minutes. Remove from the freezer and put the tray straight into the oven for 8 minutes. If you like, prepare a second sheet of cookie dough discs and put them in the freezer (see Make Ahead if you’re not going to bake all the cookies immediately).
3. After 8 minutes in the oven, the discs should have spread outwards and puffed up a little. Remove the tray and bang it down sharply on the counter, which will cause the dough to spread outwards even more, creating a ripple effect to give the cookies that crinkly, chewy texture. Put the tray back in the oven for 3 minutes, then remove and bang the tray again. Return for a final 3 minutes, then remove and let the cookies cool on a wire rack while you bake the rest of them in batches. Sprinkle with sea salt flakes and serve.