This cookie was born out of a craving for chocolate.  It is what I refer to as a ‘raid the pantry’ cookie.  I started with some deep dark cocoa and bittersweet chips.  I found toffee bits, a lot of toffee bits that were suppose to have gone into holiday cookies.  Oh well,  they’d go into my pantry cookie instead.  The reason I chose cashews comes with a confession.  During a buying spree at Costco, I just couldn’t say no to an extra large container of cashew that kept calling my name.  They became an obsession and I soon realized I was eating way too many of them on a daily basis.  I wanted to make them disappear, so into the cookies they went.  Chocolate, and more chocolate, toffee and cashews.  Sounded like a winning combination to me. 
I have made these cookies with two different types of toffee.  In the first batch I used Heath English Toffee Bits.  And in the second batch, I used Trader Joe’s Toffee Chips cut into generous pieces, about the size of a chocolate chip.  Both worked perfectly well.  The Trader Joe’s toffee is basically sugar and butter enrobed in chocolate.  All that butter and sugar melted as the cookies baked, creating buttery pockets of chewy goodness.  Any toffee will work in this cookie, with slightly varying results.
Personally, I like my chocolate chip cookies crispy on the edges and with a little chew in the center.  Using half bread flour along with the all-purpose flour helps achieve that result.  If you don’t have bread flour, by all means use all-purpose flour for the total amount of flour called for in the recipe.  One last note.  If you have any self-control what-so-ever, this cookie is much better if allowed to chill overnight in the fridge.  I don’t want to get all scientific on you, just trust me, it’s a fact.  However, if you just have to have a cookie immediately, go ahead and bake off a half-dozen or so.  Then, using all the self-control you can muster, put the rest of the dough in the fridge to rest until the following day.