Sift together the flour, cocoa powder, bicarbonate of soda, baking powder and salt

In another bowl, beat the butter and sugars together until smooth and creamy. Beat in the egg and vanilla essence.

Add the flour mixture to the butter mixture and bring together to form a dough, then add in the chocolate chips (you may find using your hands easier!)

Form the dough into one or two log shapes about 3cm (1½") in diameter and roll up in some greaseproof paper

Put the dough in the fridge for a couple of hours to firm up - you can leave the dough for long (a day or two) if you need to, just allow to come to room temperature a little before slicing - I found that easier.

When you are ready to bake, pre-heat the oven to 160C/350F/Gas 4.

Slice the triple choc dough into ½cm (¼") discs and place onto a baking sheet about 4cm (1½") apart

Bake for 12-14 minutes

Transfer to a wire rack to cool.

Can be stored in an airtight container for 5-7 days - but they probably won't last that long due to being gobbled up!!