Honey-roasted cashews offer up a rich sweetness in these slice and bake cookies.
in a large bowl combine butter and the 1/2 cup shortening. Beat with an electric mixer on medium to high speed for 30 seconds. Add brown sugar, baking soda, and salt. Beat until combined, scraping side of bowl occasionally. Beat in egg and vanilla. Beat in as much of the flour as you can with the mixer. Using a wooden spoon, stir in any remaining flour and the 3/4 cup ground nuts.
Divide dough in half. On parchment paper or waxed paper, shape each half into a 10-inch roll, lifting paper to help shape the rolls. Roll in the 2/3 cup finely chopped nuts. Wrap each roll in plastic wrap or waxed paper. Chill about 4 hours or until dough is firm enough to slice.
Preheat oven to 375 degrees F. Using a serrated knife, cut rolls into 1/4-inch slices. Place slices 1 inch apart on an ungreased cookie sheet. Bake in preheated oven for 8 to 10 minutes or until edges are firm. Transfer cookies to a wire rack set over parchment paper or waxed paper; cool.
In a microwave-safe small bowl combine butterscotch pieces and the 2 tablespoons shortening. Microwave on 50 percent power (medium) about 2 minutes or until melted and smooth, stirring two or three times.
Drizzle butterscotch mixture over cookies. If desired, top each cookie with a cashew half; let stand until butterscotch mixture is set. Makes 72 cookies.
Place in layers separated by waxed paper in an airtight container; cover. Store at room temperature for up to 3 days or freeze for up to 3 months.