Preheat the oven to 180ºC. Line a baking tray with baking paper.
Cream together the butter, sugar, condensed milk and vanilla until light and fluffy. Sift the flour and baking powder together and mix into the creamed mixture, followed by the chocolate chips.
Roll tablespoonfuls of the mixture into balls, place on the prepared tray and flatten with a floured fork.
Bake for 20 minutes until golden. Leave on the tray for 1–2 minutes then place on a wire rack to cool.