To make the base, add the hazel nuts into a food processor and blitz to form a rough flour. 

Add in the remaining ingredients and blend until sticky and well combined. 

Press this into the base of a brownie tray and pop into the freezer to chill. 

Meanwhile, combine all of the caramel ingredients in the food processor and blend everything together until you're left with a smooth caramel. 

Spread this over the base and add a touch of sea salt before returning these to the freezer. 

For the final stage, melt the chocolate and coconut oil together, then pour this over the caramel bars. Allow these to set in the freezer for 4 hours or overnight. 

Using a knife dipped in hot water, carefully slice into portions and dig in!