Bake and cool cookies of your choice. Line up cookies on a wire baking rack with a large baking sheet beneath. This will help catch any excess ganache and salt as you "dress" the cookies.
Pour butterscotch chips into a medium bowl and set aside.
Heat the heavy cream until almost boiling (in the microwave or in a small saucepan on the stove). Pour hot cream over the bowl of chips and set aside for 1-2 minutes. Stir mixture slowly, preferably with a small whisk. Continue to stir as needed until the chips are fully melted and the cream has been fully incorporated (this make take several minutes).
Allow the mixture to cool several minutes. You want the mixture to cool and thicken a bit, but still be pourable. Once it's reached a nice consistency, use a small spoon to drizzle the ganache over your choice of cookies.
As soon as you have added the ganache to 3-4 cookies, immediately add a sprinkling of very good quality sea salt, such as fleur de sel. Allow ganache to set up (20 minutes or so) before packing cookies or storing them.
The final ganache will set up firm enough to package cookies in a single layer (not stacked). You can stack them if you chose, but the ganache may get a bit smashed.
I used Guittard butterscotch chips and Esprit Du Sel Fleur de sel salt.