Preheat the oven to 165C and line 3 baking sheets with baking paper.

Sift the flour, salt and baking soda and set aside.

Using an electric mixer beat the melted butter, vanilla, espresso powder and sugar for about 2 minutes. Add the eggs and continue to beat until light and fluffy.

Add the remaining dry ingredients and mix briefly until just combined.

Stir in the chocolate chips by hand.

You can make either big or small cookies, but I like around 20ml of cookie dough scooped into more or less even balls, allowing 3cm between the cookies for spreading.

Lightly sprinkle each cookie with a little sea salt (optional), and bake for 10 – 12 minutes for a softer and smaller cookie, or a little longer – 15 – 17 minutes for a bigger and crunchier cookie.