Preheat your oven to 350 degrees F and prepare an 8×8-inch baking pan by lining it with parchment paper. Leave a few inches overhang on two sides so you can easily lift the bars out once they’ve cooled.
Next, add the diced peaches to a medium bowl. Stir gently with the fresh lemon juice. This not only adds flavor but also prevents browning, keeping your peaches looking vibrant. Then, sprinkle the cornstarch and sugar over the peaches and stir gently, allowing them to sit while you prepare the crust.
In a separate medium bowl, combine the rolled oats, all-purpose flour, sugar, melted butter, milk, salt, and cinnamon. Mix until it holds together easily when pressed between your fingers. This mixture should feel crumbly yet slightly sticky.
Set aside 1 cup of this batter to use as the topping. This is key for that delicious, crumbled finish on top of your bars.
Now, take the remaining batter and press it evenly into the bottom of your prepared baking pan. Make sure it’s compact and covers the base well; this will give your Peach Crumb Bars a solid foundation.
Add the peaches on top of the crust, using a slotted spoon to keep excess liquid from making the crust soggy. Distributing them evenly ensures that every bite is loaded with sweet peaches.
Now crumble the reserved topping over the peaches and press down slightly to help it stick. This creates a beautiful textured topping that will bake to a golden brown.
Place your pan in the oven and bake for 32 to 35 minutes, or until the top is lightly golden brown. The aroma will fill your kitchen, and you might find it hard to resist peeking!
Once done, remove the baking pan from the oven and allow it to cool completely in the pan. This helps the bars set properly. Use the parchment overhang to lift the bars out when they’re cool, and slice them into squares.