Preheat oven to 180 C (360 F). Line two baking trays with baking or parchment paper.

In a large mixing bowl, add butter and sugar and beat using an electric beater for a minute or two until smooth and creamy. Add egg and beat until combined, scrapping down the sides.

Add flour and baking soda and beat until combined. Add Nutella and beat VERY briefly until cookie dough is swirled but not completely mixed through.

Take 1.5 tablespoons of the cookie dough and roll into balls and place on baking trays, leaving room for the cookies to flatten out. Place in oven for 10-12 minutes or until golden brown on the edges.

Transfer to a wire rack to cool completely then enjoy.