Heat oven to 170c

Line a baking tray with greaseproof paper

Sieve the flour, bicarb and salt into a bowl

In another bowl, cream together the melted butter, brown sugar and caster sugar until well blended. Beat in the vanilla, egg and egg yolk until light and creamy.

Stir in the sifted ingredients until just blended.

Stir through chocolate chips using a wooden spoon.

Drop about 3spoonfuls of dough per cookie onto the baking trays

Do not flatten the dough. Cookies should be about 10cm apart.

Bake for 15 to 17 minutes in the oven, or until the edges are lightly toasted. Cool on baking trays for a few minutes then put onto cooling racks to finish cooling