How can I substitute English Toffee in cookies? I found a cookie recipe which requires "English Toffee bars". I have never seen them around here, and don't know what they are. 

What are these bars? Is there any substitution I can use? How close are Toffifee candies? 

If it just said "toffee", I would cook it at home. But I am unsure what the differences are between an English toffee bar and normal toffee. Can I still cook it? How does it differ from normal toffee? Or can I just put normal toffee in the cookies?
It's just a HARD bar of toffee. It often looks like a chocolate bar, as it is marked into break-off segments



Modern "English Toffee" recipes call for toffee with a chocolate coating dusted with chopped nuts. I don't think this is really traditional English toffee 

Use regular butter and sugar toffee as a substitute