Preheat the oven to 400ºF / 200ºC degrees.

Whisk together the flour, sugar, baking powder, baking soda, and salt. Cut in the butter until the mixture resembles breadcrumbs.

In a separate bowl, mix together the buttermilk, egg, and vanilla extract.

Stir the buttermilk mixture into the flour mixture until just incorporated, then fold in the chocolate chips and hazelnuts.

Turn the dough onto a lightly floured surface and knead very gently about 7–8 times. Pat into a circle about 6 inches wide.

Cut into 8 wedges and place each wedge onto a greased baking sheet.

Bake for 15–20 minutes, or until the tops start to turn golden brown.

Serve warm and enjoy every crumb!