In the bowl of a stand mixer, add the butter and sugars. Beat until light and fluffy, at least five minutes. Add the egg and the vanilla. Mix well.
Slowly add the flour, salt, and baking soda and mix until just combined, careful not to over mix. Add the butterscotch, nuts and chocolate and stir until all the ingredients are evenly distributed.
For each cookie, drop 2 TB dough onto ungreased baking sheets, spacing 3 inches apart. Bake for 12-14 minutes until the edges are lightly browned. Remove from the oven and let sit on the rack for 5 minutes. Remove to a cooling rack to cool completely.