Preheat oven to 200°c. Line a baking sheet with baking paper.
In a large mixing bowl, beat butter with light brown sugar and granulated sugar until the mixture lightens slightly.
Add applesauce and vanilla extract to the butter mix and combine everything well.
In a separate bowl, combine the flour, bicarb soda, baking powder and salt until combined.
Pour these dry ingredients into the butter mixture gradually and bring everything together as a dough.
Stir through your dark chocolate pieces until evenly distributed.
Spoon heaped tablespoons (or even 1/4 cups if you want larger cookies!) of the dough onto the lined baking sheet.
Optional: Place the tray of dough into the fridge and rest for 20 minutes - this will help the cookies to better keep their shape in the oven.
Place the tray in the preheated oven and bake for 12 minutes, or until the cookie is golden on top.
Remove from the oven and allow to cool on the tray for 5 minutes, before transferring to a wire rack to cool completely.