unsalted butter, cut into 9 pieces and chilled
dark brown sugar, packed
1 3/4 cups
- Microwave 1/2 cup butterscotch chips and 3 tablespoons butter in bowl until melted, about 1 minute, stirring halfway through. Whisk in vanilla until mixture is smooth. Let it cool for 10 minutes.
- In bowl whisk flour and backing powder. Set aside.
- Cream remaining butter and brown sugar with your stand mixer on medium high speed until pale and fluffy. About 3 minutes. Scrape the bowl down during this time. Add cooled butterscotch mixture and beat until combined, about 1 minute. Add egg yolk and beat until incorporated. Reduce speed to low and add in the flour/baking powder and mix for a minute, or until the dough is formed.
- Turn dough out on to the counter and shape it into a 9 inch roll to form an even cylinder. Wrap it in parchment paper, roll it again until you feel like it’s a good cylinder shape. Refrigerate for 2 hours.
- Heat the oven to 325 degrees. Line two baking sheets with parchment and slice the chilled dough into 1/4 inch rounds and place on baking sheet, and bake for 10-12 minutes.