Now for the fun part: the mix-ins. I sprinkle the butterscotch chips and toffee bits over the dough. Then, I gently fold them in until they’re evenly distributed. The dough will be thick and a bit sticky. I transfer it to my prepared pan. Using my spatula or lightly greased fingers, I press the dough into a smooth, even layer, making sure to get into all the corners. This even pressing is important for uniform baking.
I place the pan in the center of my preheated oven and bake for 22-26 minutes. The trick is to pull them out when the top looks set and is a beautiful golden brown, and the edges are just starting to pull away from the pan. The center might still look a little soft—this is perfect! It will continue to set as it cools. I learned the hard way that overbaking for even a few minutes results in a dry, crumbly bar. I let the pan cool completely on a wire rack before using the parchment paper to lift the giant cookie out to slice.
Pro Tips for Best Results
For the absolute best texture, let the melted butter cool for about 10-15 minutes before adding the sugars. If it’s too hot, it can start to cook the eggs, creating a weird texture. I’ve tried it both ways, and the slightly cooled butter gives you a much smoother, more emulsified batter that bakes up perfectly.
Don’t skip the parchment paper liner. I used to just grease the pan, but I’d always lose a corner or have a hard time getting the first bar out. The parchment paper sling guarantees you get every single crumb and allows for the cleanest, most professional-looking cuts. It’s a game-changer for bar cookies.
The most crucial tip is to not overbake. These bars are meant to be chewy. Start checking at 22 minutes. Look for golden edges and a top that has lost its glossy shine and looks matte. A toothpick inserted near the center should come out with a few moist crumbs, not clean. They firm up dramatically as they cool. Trust the process and pull them a little early if you’re unsure.
Common Mistakes to Avoid
The biggest mistake is overmixing the dough once the flour is added. I made this error in an early batch, stirring until it was completely smooth. This over-develops the gluten and makes the bars tough and more bread-like than cookie-like. Fold just until you no longer see dry flour, even if the dough looks a bit shaggy.
Don’t use hot, just-melted butter. As mentioned, this can scramble your eggs slightly and also cause the sugars to dissolve too much, affecting the texture. Let it cool until you can comfortably touch the bottom of the bowl. This small wait makes a huge difference in the final crumb.
Avoid using a glass or dark-colored pan if you can. They retain heat differently and often lead to over-browned, hard edges. A light-colored metal pan promotes the most even bake. If you only have glass, reduce the oven temperature by 25 degrees and watch the baking time closely.(See the next page below to continue…)