Pre-heat the oven to 180°C/160°C fan/gas mark 4 and grease a 12 hole friand tin.
Place the butter in a saucepan and heat over a medium flame. The butter will melt. Listen carefully and the butter will start hissing and cracking and forming little brown bits at the bottom of the pan. You want to wait until the noises start to subside, the butter smells toasty and is turning a darker colour. Remove from the heat as soon as it gets to this stage so it doesn’t begin to burn. Pour the butter into a heatproof container and set aside to cool for 5 minutes, you don’t want it too hot when you add to the rest of the ingredients.
Sift together the buckwheat flour, icing sugar, baking powder and salt.
Stir in the ground hazelnuts and the blood orange zest.
Pour in the browned butter and stir until completely combined.
Whisk the egg whites in a separate clean bowl until light and foamy.
Fold the egg whites into the rest of the batter until combined.
Divide the batter between the friand moulds then bake for 25 minutes.
Leave to cool in the tins for 10 minutes then turn out and finish cooling on a wire rack.
Make the icing by beating together the blood orange juice gradually with the icing sugar until the icing is just pourable. If the icing is a little thick then add a drop or two of water to achieve the right consistency.
Spoon the icing over the cooled friands. Sprinkle over the extra ground hazelnuts and decorate with a segment of blood orange and leave to set.
Recipe adapted from Coffee and Walnut Financiers in Sweet by Yotam Ottolenghi and Helen Goh (amazon affiliate link)