chocolate butterscotch shortbread

the goods:

2 sticks unsalted butter, softened

3/4 cup dark-brown sugar

1 teaspoon vanilla extract

2 cups flour

1 teaspoon salt

1/2 cup butterscotch chips

8 ounces dark chocolate, melted

Preheat oven to 300 degrees. In the bowl of a stand mixer using the paddle attachment, beat butter and sugar on medium-high until light in color and fluffy, about 3 minutes. Add vanilla, reduce speed to low, and slowly add flour and salt until just combined. Mix in butterscotch chips and stir until evenly distributed, scraping down paddle if needed.

Grease a 9-by-9-inch baking pan. Using a rubber spatula, press dough evenly into pan and refrigerate for 20 minutes. Score dough into eighths in one direction and quarters in the other, to make 32 rectangular cookies. Pierce dough all over with a fork.

Bake until firm and slightly golden brown around the edges, 50 to 60 minutes. Immediately cut through all the scoring to separate the cookies. Let cool completely in the pan.

Remove cookies and place on a parchment-lined baking sheet. Dip half of each cookie in chocolate, gently scraping off any excess, and place back on baking sheet. Refrigerate until chocolate is set, about 30 minutes.