Lightly grease a 9x13 baking dish or line with parchment paper.
Combine flour, salt, oats, coconut, and brown sugar in a large bowl of electric mixer and mix at low speed.
Add butter and continue mixing until a crumbly dough forms. Add egg and vanilla extract and continue mixing until combined. Stir in chocolate and butterscotch chips.
Reserve 1-1/2 cups of dough for topping. Press remaining dough into bottom prepared baking dish. (Sprinkle on some more chocolate chips if desired.)
Bake for 10 minutes.
Pour sweetened condensed milk evenly over the hot crust.
Top evenly with the reserved cookie dough.
Bake 25 to 30 minutes until golden brown. Cool and cut into bars.
Optional glaze
Combine chocolate chips and oil in a small bowl. Microwave in 30 second increments on high heat, stirring in between, until fully melted. Drizzle over top of cooled bars. Let set up before serving.