Preparing the lemon curd: Whisk egg, egg yolks, sugar, lemon juice and cornflour in a saucepan until smooth, then place pan over a low heat. Keep whisking continuously until thickened. Remove from heat and let rest.
Preparing the brownies: Preheat oven to 175°c (350°F). Line a 20x20 cm (8x8 inch) pan with parchment.
Melt the butter.
Add the eggs and sugar and whisk together.
Add the coco powder, flour and salt and fold in using a spatula, until incorporated.
Pour the brownie batter into the pan.
Using a spoon pour small heap of lemon curd onto the brownie batter. With a wood skewer swirl the batter till a marble look is formed.
Bake for 20-30 min or till brownies to begin to crust and crack, but still moist inside.
Let cool and serve.
You can keep cut brownies in a closed container in the fridge for up to a week.
Recipe by Neta Cooks at https://netacooks.com/super-fudgy-chocolate-brownie-with-lemon-curd/