Cream the margarine and sugar together in a large bowl until fluffy.
Add the egg and vanilla and beat again.
Add the flour, baking powder and bicarb and stir until fully combined.
Add 60g of the chocolate chips and mix through again.
If the dough is very soft, place in the fridge for 30 minutes to firm up.
Use an ice cream scoop to create soft balls of dough and place them on a baking sheet lined with baking parchment, leaving plenty of space for them to spread out.
Top each ball of dough with a few extra chocolate chips.
Place in the oven for 9-10 minutes until golden.
Allow to cool on the tray until firm enough to transfer to a wire rack to cool completely.