Freeze the hazelnut spread portions

• Line a small tray with parchment paper.
• Scoop the hazelnut chocolate spread into about 10 small portions, roughly one tablespoon each.
• Freeze until firm.

Preheat the oven and prepare the trays

• Preheat the oven to 175 °C.
• Line two baking trays with parchment paper.

Cream the butter and sugars

• In a large mixing bowl, combine the cold cubed butter, brown sugar and granulated sugar.
• Using a paddle attachment, beat on medium speed until combined and creamy-looking.

Add the eggs and vanilla

• Add the egg, egg yolk and vanilla bean paste.
• Mix until fully incorporated, scraping down the bowl as needed.

Whisk the dry ingredients

• In a separate bowl, whisk together the flour, espresso powder, baking powder, baking soda, salt and cornstarch.

Combine the dough

• Gradually add the dry ingredients to the wet ingredients.
• Mix on low speed just until the flour disappears, without overmixing.
• Fold in the semi-sweet chocolate chips and chopped Kinder Bueno pieces.

Stuff and shape the cookies

• Divide the dough into approximately 10 portions.
• Flatten each portion slightly, place one frozen hazelnut-spread portion in the center along with Kinder wafer chocolate, then fold the dough completely around it.
• Seal well and roll into a tall, thick ball.

Chill the shaped cookies

• For the thickest bakery-style result, chill the shaped cookies.

Bake the cookies

• Place the cookies on the prepared baking trays, leaving plenty of space between them.
• Bake at 175 °C until the edges are golden brown and set while the centers still look slightly soft.

Cool the cookies

• Let the cookies cool on the baking tray.
• Transfer to a wire rack.