Seperate the eggs and place 2 yolks into a mixing bowl and the 6 whites into another mixing bowl. Pour the buttermilk, melted butter and vanilla extract in with the egg yolks and whisk until combined. Tip the flour and the baking powder into the bowl, zest in the lemons and stir to a thick, smooth batter.
Tip the cream of tartar in to the bowl with the egg whites and whisk to stiff peaks adding the 50g sugar gradually as you whisk. Fold the egg whites into the batter in 3 parts, keeping as much air as possible in the mix.
Preheat a non-stick frying pan over a low heat with some of the 2 tbsp of butter. Place a greased 10cm metal ring into the pan and scoop the batter into the ring, filling almost to the top. Cook gently for 5 minutes then carefully flip in the ring. Cook for another 5 minutes and transfer to your serving plates. Add more butter and repeat for the rest of the batter.
Tip the 220g of sugar into a small saucepan and cover it with the water. Put the saucepan over a high heat. Let it bubble away until it begins to thicken and get sticky. Add the yuzu juice and continue to bubble until it thickens again. Add the blueberries to the warm syrup and remove from the heat.
Stack the pancakes onto plates and pour over the syrup and blueberries.