Preheat the oven to 200℃/400℉. Line a large baking tray.
Slice the four croissants in half along the long side to create an opening.
Fill each croissant with about 2 tablespoons each of the chocolate hazelnut spread. Scatter over crushed Kinder Buenos. Close each croissant.
Top with a drizzle of warmed up chocolate hazelnut spread. Bake 10 minutes, until golden!
Dust with powdered sugar using a sieve for even distribution. Serve warm!