Slide the pan into the center of your preheated oven. The bake time is crucial. I set my timer for 25 minutes and start watching. You’re looking for a deep, golden brown crust on top, and the edges will just barely begin to pull away from the sides of the pan. A toothpick inserted in the center will come out clean or with just a few moist crumbs, but no wet batter. Do not overbake! Overbaking is the enemy of the soft, tender center. Let the pan cool completely on a wire rack before you even think about cutting into it.
Pro Tips for Best Results
I tested this three different ways: mixing by hand, using a stand mixer on low, and using a hand mixer. Mixing by hand is definitively the best method. The stand mixer, even on low, incorporated too much air and made the texture slightly foamy and less tender. The hand mixer created pockets of dry mix. The manual stir gives you the most control and the perfect, slightly dense yet soft crumb.
For the cleanest cuts and most beautiful bars, patience is your best friend. I know it’s tempting to dive in while they’re warm, but if you cut them before they’re fully cooled, they will tear and crumble. I let mine cool in the pan on a rack for at least 2 hours. For perfect squares, I even pop the whole pan in the fridge for 30 minutes after it cools to really firm up the center layer before slicing with a sharp knife.
If you want an extra burst of lemon flavor and a professional finish, a simple glaze is magical. While the bars cool, I whisk together 1 cup of powdered sugar with 1-2 tablespoons of fresh lemon juice until smooth. I drizzle this over the completely cooled bars. It adds a lovely sweetness and an extra punch of citrus that takes them from fantastic to phenomenal. It’s a third “almost ingredient” that feels fancy.
Common Mistakes to Avoid
My first big mistake was using the wrong size pan. I once tried to spread this into a smaller 8×8 pan, thinking it would be thicker and fudgier. It was a disaster. The center was still raw when the top was burnt because the batter was too deep. The 9×13 pan is non-negotiable for proper heat distribution and baking. Don’t try to change it.(See the next page below to continue…)