Step 1

For the crust and topping: Preheat the oven to 350˚F. Spray a 9-by-13-inch baking pan with cooking spray. Line the pan with parchment paper. (This will make it easier to lift the pie bars out of the pan after baking.)

Step 2

In a large bowl using an electric mixer, beat the butter, sugars, and vanilla until combined and airy, 4 to 5 minutes. Scrape down the sides and bottom of the bowl. Add the flour and salt to the bowl and mix on low speed until combined.

Step 3

With lightly moistened hands, press about 3/4 of the crust mixture along the bottom and slightly up the sides of the prepared pan. Refrigerate for 15 minutes. Place the remaining 1/4 of the crust mixture (about 1 1/2 cups) in the refrigerator until needed.

Step 4

Transfer the pan to the preheated oven and bake until the crust is golden brown, 20 to 25 minutes. Place on a wire rack to cool.

Step 5

For the filling: In a large bowl, toss the apple slices with the vinegar. Add the brown sugar, cornstarch, apple pie spice, and salt, and toss well to coat. Spread the apples evenly over the crust, leaving a small border around the edges.

Step 6

Tear the reserved crust mixture into small pieces. Using your hands, combine the pecans with the dough and scatter the mixture evenly over top of the apples. Bake for 1 hour, rotating the pan halfway through, until the apples are fork tender and the topping is golden brown. Cool completely in the pan, about 1 to 2 hours

Step 7

For the glaze: In a medium bowl, combine the maple syrup, butter, cream cheese, confectioner's sugar, and milk or cream. Whisk until combined and smooth. Once the bars are cool, lift from the pan using the parchment paper overhang and place on a cutting board. Drizzle evenly with the glaze. Cut into squares and serve.