Preheat the oven to 190 C / Gas 5. Line a baking tray with baking parchment.
Combine the brown sugar and butter in a large bowl and beat until creamy. Add the egg and mix until pale and looser, followed by the vanilla extract and mix well. Fold in the flour, baking powder and salt until well combined. Finally stir through the chocolate chips and mix until the chocolate is evenly distributed.
Use a teaspoon to scoop small balls of cookie dough on to the prepared baking tray. Leave a space around each scoop so that they have room to spread.
Bake the cookies in the oven for 8 to 10 minutes until firm and golden brown. Larger cookies may need longer. Remove from the oven and leave to cool on a cooling rack then ENJOY!