Step 1

Preheat oven to 350°. Line a 9×13” baking dish with foil and spray with cooking spray.

Step 2

Beat butter, sugar, peanut butter, and egg yolk on medium-high speed in an electric mixer until smooth. Scrape down the sides of the bowl. Add the flour, oats, and salt and beat on low until just combined.

Step 3

Press the mixture into the bottom of the prepared pan. Bake 15-20 minutes until the top is golden. (Be careful not to over bake!)

Step 4

Remove the pan from the oven and scatter the chocolate chips evenly over crust. Place pan back in oven for 1 minute. Remove the pan and spread the melting chocolate chips evenly with an offset spatula. Sprinkle the toffee bits evenly over the top and gently press them into place.

Step 5

Set on a rack to cool until the chocolate has hardened, at least 2 hours. Remove from pan using foil. Cut into squares while room temperature. Store in the refrigerator for maximum freshness. (Bars can also be frozen for later use.)