Preheat oven to 200c/180c Fan/Gas 6. Line 2 large baking trays.
In a large bowl, combine the oil, golden syrup peanut butter and both sugars until fully combined into a sticky mixture. Fold in the flour and baking soda until a cookie dough forms.
Fold in the chopped chocolate. Create 8 balls of the dough (a large tablespoon of mixture each) and place on the trays, spaced apart. Press down before baking for 12-15 minutes. Let cool on a wire rack.