1-First Step: Heat the oven and brown the butter Start by heating your oven to 350°F. Place the 1 1/2 sticks of unsalted butter in a skillet and cook it over medium heat until it turns golden brown and smells nutty. This usually takes about 8 to 10 minutes. Stir often so the butter browns evenly and does not burn. Once the butter is browned, stir in the 3/4 teaspoon kosher salt and set it aside for a few minutes so it cools slightly. Browning the butter is worth the small extra effort because it gives the crust a toasted, rich flavor that plain butter just cannot match. If you are short on time, regular melted butter will still work, but the flavor will be milder.

2-Second Step: Prepare the pan and mix the dry ingredients Line an 8×8-inch baking pan with parchment paper, leaving enough overhang so you can lift the bars out later. This makes cleanup easier and helps the bars release cleanly after baking. In a large bowl, combine 2 cups all-purpose flour, 1/3 cup granulated sugar, 1/3 cup packed light brown sugar, and 3/4 teaspoon baking powder. Stir everything together so the dry ingredients are evenly mixed. Then pour in the browned butter and mix until the dough starts to come together. It should look crumbly at first, then form a soft dough when pressed.

3-Third Step: Build the crust Reserve 3/4 cup of the dough for the topping. Press the remaining dough evenly into the prepared pan. Try to pack it down into one smooth layer so it bakes evenly and supports the apple filling later. Bake the crust for 15 minutes. It should look set and slightly dry on top, but not fully browned yet. This short pre-bake helps keep the bottom from getting soggy once the apples go on top.

4-Fourth Step: Make the apple filling While the crust bakes, increase the oven temperature to 375°F. In another bowl, whisk together 2 large eggs, 1/3 cup granulated sugar, 1/3 cup packed light brown sugar, 2 tablespoons all-purpose flour, 2 tablespoons heavy cream, 1 teaspoon apple pie spice, and 1/4 teaspoon kosher salt. Whisk until the mixture looks smooth and fully combined. Then add the 1 1/4 pounds of sliced apples and toss everything together until the fruit is coated. The flour helps thicken the filling as it bakes, while the cream gives it a soft, custardy texture.

5-Fifth Step: Layer and bake Take the pan out of the oven and carefully spread the apple mixture over the baked crust. Make sure the apples are in an even layer so the bars bake at the same rate across the pan. Crumble the reserved dough over the top. It will not cover every inch, and that is exactly what you want because the gaps let the apples peek through. Bake for 55 to 60 minutes at 375°F. The top should be golden, and the filling should look thickened and set around the edges. If the top is browning too quickly, loosely tent the pan with foil during the last part of baking. Since ovens vary, begin checking near the 50-minute mark.

6-Final Step: Cool, slice, and serve Let the bars cool completely in the pan, which takes about 2 hours. This cooling step matters because the filling firms up as it rests. If you cut too soon, the bars may fall apart and the apple layer can seem runny. Once fully cooled, lift the bars out using the parchment paper and cut them into 12 to 16 pieces. Serve them as they are, or add a small scoop of vanilla ice cream if you want a dessert-style finish. These bars are especially good with coffee, black tea, or warm cider.