The phrase "hazelnut flavour" refers to the taste or scent that resembles or reminds you of hazelnuts, which are small, round nuts with a sweet and nutty taste. Full definition
For how little ingredients are in them I really love the subtle hazelnut flavour. (havecakewilltravel.com)
The cheesecake layer had a fabulously pronounced chocolate hazelnut flavour and was super creamy, as opposed to dense and crumbly as some cheesecakes can be. (gottagetbaked.com)
This no bake Nutella cheesecake is packed full of hazelnut flavour. (bakesbychichi.com)