**This recipe requires chilling, so prepare for that.**
In the bowl of an electric mixer fitted with the paddle attachment (or using a hand mixer), cream melted butter and sugar. Mix in vanilla and egg until smooth. Mix in pudding mix (just the powdery mix, not actual pudding). Mix in salt, baking soda, and then flour, mixing until well blended. Let the dough sit for 5 minutes, then stir in 1 cup of butterscotch chips and nuts.
Drop cookie dough balls (I used a 2 tablespoon cookie scoop) onto 2 cookie sheets that have been lined with silpat baking mats or parchment paper. Press a few of the remaining butterscotch chips onto the top each cookie. (You can do the same with extra cashews if you wish.) The pressing on top just makes them prettier, but is not necessary. Slightly press the balls down with the palm of your hand - very gently. Chill for at least 30 minutes.
Preheat oven to 350°F. Bake for 11-14 minutes, until the edges lose their sheen. I like them a little under done at about 11-12 minutes, but if you like your cookies more done, cooke them a few minutes longer.