Just came up in my mind after a shift at work. Thought amaretto would go well with the hazelnut, but it would also need a bit of vodka to add a kick but...
Initially a little bit too sweet for me so I added 5ml of lemon juice and 2 dashes of orange bitters and that balanced it nicely. I will try this again with a higher ml of lemon as I think it can take it. Also used lemon peel; expressed and as garnish.