PREPARE: Heat oven to 180°C / 350°F / Gas 4 and line an oven tray with baking parchment paper.

BEAT SUGAR AND EGGS: In the bowl of a stand mixer with the paddle attachment fitted, beat the sugar, eggs and salt together until light and fluffy.

ADD DRY INGREDIENTS: Sift over the flour, cocoa powder and baking soda, and run the mixer on low speed until a crumbly dough begins to form. Add the hazelnuts and mix for a minute more, then turn out onto the bench top and knead briefly until smooth.

SHAPE AND FIRST BAKE: Divide dough into two pieces, shape into logs approximately 30cm (12 in.) long and place them on the prepared baking tray, allowing enough room for the biscotti to spread. Bake for 25 minutes, until crisp on the outside.

SLICE: Remove from the oven and allow to cool for 5 minutes on the baking sheet. Use a sharp knife to cut the logs on a diagonal into slices 1.5cm (just more than ½ in.) wide. I cut them directly on the baking sheet, but you can use a cutting board if you prefer,

SECOND BAKE: Flip each slice so that a cut side is facing upwards, then return to the oven and bake a further 10-15 minutes to crisp. Allow to cool on the tray for 5 minutes, before transferring to a wire rack to cool completely.