To avoid sticking, spray a brownie tray with Frylight and preheat the oven to 180°C (160°F for fans) or gas mark 4.
Mix the flour, cocoa powder, sweetener, baking powder, and options in a big bowl.
Add the beaten eggs gradually, using a wooden spoon to beat them well.
Add vanilla essence and water, and stir.
Using a metal spoon, fold in the yoghurt.
Fold the little pieces of Curly Wurly into the mixture after breaking them up.
After adding the batter to the brownie pan, bake it for 15 to 20 minutes.
If a sharp knife inserted in the centre of the mixture emerges clean, the food is cooked. Return to the oven for an additional five minutes if there is still a mixture visible on the knife.
After cooling on a wire rack, cut into 18 squares.