Break the Kinder Buenos into small pieces and roast the hazelnuts.
Place the hazelnuts on a tray in the oven at 180°C (350°F) and roast for 10 minutes. Allow them to cool and peel the skins off as many of them as you can.Place them in a food processor and pulse until crushed into small pieces.
Line a 9"x9" baking tin with cooking paper and preheat the oven to 180°C (350°).
Melt the butter and chocolate together.
Beat the eggs, sugar and vanilla extract until light and fluffy.
Mix the chocolate mixture through the eggs.
Mix in the cocoa, followed by the flour.
Chop the kinder Bueno and Kinder chocolate into small pieces.
Mix in the chocolate chips, crushed hazelnuts and Kinder Buenos and pour into the prepared pan.
Place in the oven for 20-25 minutes until the sides and top are set with a slight wobble in the centre.
Allow to cool slightly before topping with the remaining Kinder Bueno and Kinder chocolate. Melt the milk chocolate and drizzle over the brownies.