Heat oven to 180C/160C fan/gas 4 and line two baking sheets with parchment

Cream the butter and both sugars together until very light and fluffy, then beat in the egg and vanilla.

Stir in the flour, bicarb, chocolate and ¼ tsp salt

Scoop 10 large dessertspoons of the mix onto the trays, leaving enough space between each to allow for spreading. Just leave them as you put them on, no need to flatten or spread the cookie mix.

Bake for 10-12 mins or until firm at the edges but still soft in the middle – they will harden a little as they cool.

Leave to cool on the tray for a few mins before eating warm, or transfer to a wire rack to cool completely.