1Preheat oven to moderately slow, 160 C. Line 3 oven trays with baking paper.
2In a bowl, using an electric mixer, beat butter, sugars and vanilla together until pale and creamy. Beat in egg and yolk until fluffy and well combined.
3Sift flour and soda together into a bowl. Fold through creamed mixture with choc chips and hazelnuts.
4Roll heaped tablespoons of mixture into balls and arrange on trays, 5 cm apart. Flatten slightly using floured fingertips.
5Bake 10 to 15 mins, until golden. Cool on trays 5 mins before transferring to wire racks to cool completely. Store in an airtight container.
TIP: You can use any combination of choc chips for these cookies.
Photo: Rob Shaw/BauerSyndication.com.au