Line an 8 by 8 baking pan with aluminum foil. Generously butter the foil and spread the cashews over the bottom of the pan.

In a medium saucepan add the butter and brown sugar. Over medium heat bring this to a boil.

Boil for 7 minutes, making sure that you keep stirring the mixture so it does not burn.

After 7 minutes remove the pan from the heat and stir in the vanilla.

Quickly pour the toffee over the nuts. (Make sure to pour the toffee over as much of the pan as possible, it hardens quickly so it is hard to spread).

Spread the mixture to cover the nuts.

Sprinkle the chocolate chips over the hot toffee and spread the chips until melted.

Let the toffee cool completely.

Remove from the baking pan and then remove the aluminum foil from the toffee.

Cut into desired pieces.