Begin by combining the Oatbran, baking powder, corn flour and sea salt. Melt the butter and allow to cool, then with a hand blender combine with the sugar until smooth. Next add in the whisked eggs and vanilla extract and gradually add in the flour mix. Gently fold in your chocolate chips, pistachios and finely chopped lavender, spooning it into the mixture in small quantities and gently folding so that you get an even distribution of small pockets of flavour.
Next cover with cling film and place in fridge for at least thirty minutes, ideally an hour if you can. Preheat the oven to 190 degrees Celsius then make rough balls a little smaller than a golf ball and place on parchment paper or a nonstick baking tray leaving enough room for the cookies to spread out. Cook for 10-12 minutes or until the edges start to turn golden (only just) and the center is still soft and slightly uncooked. Allow to cool or eat while warm if you can’t wait.
Store in an airtight container.