preheat oven to 180°

mix the butter and sugar together then add the vanilla essence,egg yolk, sugar and flour until combined, then add the chocolate chips, use hands to mix into a dough.

Then once the dough is made make little balls with the dough, place the balls onto some grease proof paper and squash them to make a cookie shape, space them evenly as they will spread slightly.

place in oven for 15-20 minutes and then transfer to a cooling rack.