• Preheat the oven to 170°C.
• Combine the butter and sugars in a stand mixer fitted with the whisk attachment. Beat together on medium speed until well combined and lightly coloured. Do not overmix.
• Add the eggs, one at a time, mixing well after each addition.
• Add the remaining ingredients and whisk on low speed until well combined.
• Line three baking trays with baking paper. 
• Shape the cookie dough into 45g balls and place on the trays, spaced about 3cm apart to allow for spreading. Gently flatten them to about 1cm  thick, then make a small dent in the centre of each cookie with your finger.
• Place a generous 1½ teaspoons of Nutella in each of the dents. 
• Sprinkle each cookie with a little sea salt.
• Bake for 15 minutes, then transfer to a wire rack and leave to cool and crisp up before serving.

Adapted from Feasting by Amanda Ruben (Hardie Grant, £25)