Preheat oven to 200°c and line a baking tray with baking paper. In a large bowl, combine brussels sprouts, sugar and marmalade and season with salt and pepper to taste. Arrange sprouts evenly over the lined tray and place in the oven to roast. Turn after 20 minutes and continue roasting for a further 20 minutes.
In the mean time, cook the bacon over a medium heat until crisp. Then, transfer to a paper towel lined plate.
Place the brussels sprout mixture in a serving bowl. Toss with the bacon and hazelnut to serve.