1 Beat the butter, sugar and syrup together in a food mixer with a paddle attachment until light and fluffy.
2 Beat the egg in a separate bowl and mix in the vanilla paste then mix into the beaten butter and sugar.
3 Fold in the remaining ingredients except the marshmallow pieces. Mix well to form a cookie dough.
4 Split the dough into 40g balls and place them on a Pyrex glass baking tray lined with baking parchment. Flatten the dough balls slightly leaving enough room for them to spread.
5 Chill the cookie dough for at least an hour before baking in a preheated 180°C oven.
Recipe courtesy of Pyrex