Preheat your oven to 180C / 350F and adjust your oven rack to the middle shelf.
Line three baking trays with parchment paper and set aside.
Using a stand mixer, or in a large bowl with an electric whisk, beat the butter for 1 minute until pale, soft and creamy. Add in the granulated and brown sugars, then beat on a medium speed for 3-5 minutes until light and fluffy.
Scrape down the sides of your bowl using a rubber spatula then add the eggs, vanilla bean paste and sweet miso paste. Beat again until well mixed.
Sift in the flour, bicarbonate of soda and salt and beat on a low speed until just combined.
Chop your chocolate and your hazelnuts, then add them to the dough, mixing with a spatula so everything is well incorporated. Pour the sesame seeds into a bowl.
Using a size 20 cookie scoop (or measuring out 50g balls of dough), scoop your dough into balls then roll immediately in the sesame seeds.
Place a few cookies on the prepared baking trays, at least 1 inch apart to allow them to spread and bake for 10 minutes until a little puffed up in the centre.
Remove the tray from the oven and give the tray a slight knock on top of the oven to flatten them out a bit. Return the cookies to the oven, rotating them 180 degrees and bake for a further 5 minutes until they're just turning a beautiful golden brown.
Remove the tray from the oven and give them one final knock on top of the oven before leaving them to cool on the tray for 10 minutes before transferring to a wire rack to cool completely.
Store the cookies in an airtight container for up to 5 days.