Preheat the oven to 160°C / 325°F / Gas mark 3.
Grease a large loaf tin and line with a long strip of baking paper.
Put 100g of yoghurt, 2 tablespoons of lemon curd, the softened butter, eggs, lemon zest, flour and caster sugar into the food processor and pulse until the batter just comes together.
Scrape half into the prepared tin.
Scatter 85g of the blueberries over the batter then scrape the rest of the batter on top, then scatter the other half of the berries on top.
Bake for 1 hour 10 minutes or until golden, and a skewer poked into the centre comes out clean.
Cool in the tin, then carefully lift onto a serving plate.
Sift the icing sugar into a bowl and stir in enough lemon juice to make a thick, smooth icing.
Spread over the top of the cake, then decorate with extra blueberries and serve with the extra yoghurt and lemon curd.