I slide the pan into the center of my preheated 350°F (175°C) oven. I bake for 22-26 minutes. This timing is everything. I look for the edges to be pulling away from the pan and turning a deep golden brown, and the top should be set and crackled. A toothpick inserted in the center should come out with a few moist crumbs, but no wet batter. The hardest part is waiting, but I let the pan cool completely on a wire rack before I even think about lifting out the slab and cutting it. This cooling time is what allows the bars to set up for the perfect chewy texture.
Pro Tips for Best Results
I tested the pan size three different ways: in an 8×8, a 9×9, and a 9×13. The 8×8 pan is non-negotiable for the perfect thickness. In a 9×9, the bars were too thin and baked up crisp, losing that wonderful chewy density. The 9×13 was a disaster—they were like thin, overcooked cookies. For the ideal texture Trisha intended, the 8×8 pan is a must. Trust me, this one works better.
For the cleanest, most beautiful cuts, I use the parchment sling to lift the entire cooled slab onto a cutting board. I use a sharp chef’s knife, not a serrated one. I wipe the blade clean with a damp cloth between each cut to prevent dragging and tearing. This gives you those pristine, sharp edges that make the bars look bakery-perfect.
If you want an extra layer of flavor and a beautiful finish, sprinkle the top with a light dusting of flaky sea salt as soon as the bars come out of the oven. The heat helps it adhere. The tiny bursts of saltiness against the rich, sweet butterscotch are absolutely transcendent and take these humble bars to a whole new level.
Common Mistakes to Avoid
My first-time mistake was overbaking. I waited until the top was uniformly brown and a toothpick came out completely clean. The result was a dry, almost crunchy bar that lacked the fudgy, chewy heart. These bars are done when the edges are firm and browned but the center still seems a bit soft. They continue to cook from residual heat in the pan. Underbaking slightly is better than overbaking here.(See the next page below to continue…)