Freeze the Nutella portions

• Cut cling wrap into small squares.
• Scoop a teaspoon of Nutella onto each square, fold to seal and freeze until solid.

Make the cookie dough

• Whisk the cubed butter in a large bowl until slightly creamy.
• Add the caster sugar and light brown sugar and whisk until fluffy.
• Whisk in the egg, egg yolk and vanilla until fully incorporated.
• Mix in the baking powder, baking soda and salt, then fold in the flour mixed with cinnamon until just combined.

Prepare the cinnamon sugar

• Mix the cinnamon powder and caster sugar in a separate bowl and set aside.

Stuff and coat the cookies

• Portion the dough into balls.
• Press a frozen Nutella piece into the centre of each ball, seal well and roll into a ball.
• Coat each dough ball with the cinnamon sugar mixture and place on a baking tray.

Bake

• Preheat a fan oven to 175-180 °C.
• Bake until the tops are lightly golden while the centres remain soft.

Cool and coat again

• Remove from the oven and let cool.
• Coat the cookies again with the cinnamon sugar mixture.

Dip in chocolate

• Melt the chocolate bar using the double boiler method.
• Coat the bottom of each cookie with melted chocolate and set aside to set.