Preheat the oven to 200 °C. Line the base of an 18 – 19 cm spring form cake tin with baking paper and grease the sides. Sift the flour, baking powder, vanilla powder and Hermesetas Granulated together in a bowl. Melt the butter and break the eggs into a bowl and then add the melted butter. Add the buttermilk and the lemon juice and finely grated lemon peel.
Pour the liquid ingredients into a bowl with the flour mixture while beating it. Stir the dough until it is free of lumps. Pour the batter into the spring form cake tin and bake in the oven for 30 minutes or until it is baked through. Remove the cake and allow it to cool on a wire rack.
Garnish the cake with melted white chocolate.