For the cookie dough: Add butter and sugar to a mixing bowl. Use an electric mixer to mix the butter and sugar together. Mix in vanilla and egg.
Add flour and baking soda and mix until dough forms.
Shape dough into a log about 10" long, wrap in plastic wrap and refrigerate for at least one hour.
When ready to slice and bake Preheat oven to 350 F. degrees.
Remove dough from fridge and slice cookies to desired thickness. I tried to make mine a little on the thick side about ¼" thick.
Place on an ungreased cookie sheet leaving space between cookies because they will expand.
Bake for 8-10 minutes or until cookies look set. I cooked mine for about 9-10 minutes since I wanted them to be soft, bake longer if you want a crisper cookie.
For the frosting: Once the cookies have cooled you can make the frosting. Add ingredients to a mixing bowl and use an electric mixer to whip frosting together, I mixed for 1-2 minutes. Frost cookies and top with sprinkles if desired. Above is a recipe for butterscotch sauce which I think makes the frosting taste amazing. You can make it while you are waiting for the cookies to cool so it will be ready when you make the frosting, or you can just use store bought caramel sauce.
For butterscotch sauce: Mix ingredients together in a saucepan over medium heat. Stir for about 5 minutes until it gets a little thicker. It will thicken more once cool. Set aside until it cools completely then add to the frosting.
Recipe by THE SEMISWEET SISTERS at https://www.thesemisweetsisters.com/2022/03/12/slice-and-bake-sugar-cookies-with-vanilla-butterscotch-frosting/