Place butter, condensed milk and golden syrup into a saucepan.
Stir the mixture over low heat until the butter is melted, simmer for 2 minutes
Add the biscuit crumbs and almonds, stir to combine well.
Press firmly into the lined slice tray.
Topping
Melt the chocolate and copha either in the microwave in 30 second bouts or heat very carefully in a saucepan over low heat, stirring until smooth.
Add the hazelnuts if not using hazelnut chocolate, stirring well.
Pour the chocolate mixture over the base and refrigerate approximately 2 hours or until set.
Remove the slice from the fridge 30 minutes before slicing, to help the chocolate not to crack.
Notes
Like most of my slices I freeze portions so we don't consume it all at once.I cut my slices into 12-36 pieces depending on what they are being used for.