Preheat the oven to 180° C.
Heat a deep non-stick pan, add the butter and let it melt. Add the Sugarfree Natura and two tablespoons water and mix till the sugar dissolves.
Take the pan off the heat, add the chocolate chips and stir till they melt. Transfer into a bowl.
Sift the refined flour, salt and soda bicarbonate into another bowl.
Add the vanilla essence to the chocolate mixture and mix well. Add the orange peel and mix.
Add one egg at a time and mix well. Add the flour mixture and mix till well incorporated.
Grease an oven proof glass dish, pour the batter into it and bake in the preheated oven for fifty to fifty five minutes.
Remove from the oven and let the brownie cool before cutting into squares. Serve.