Preheat the oven to 350F degrees and line a jelly roll baking pan with parchment paper or spray with non-stick spray and set aside.
Whisk together the flour, sugar, baking powder and salt.
Using an electric mixer, beat in 4-5 tablespoons of butter at a time until the mixture forms a crumbly consistency.
Add the egg and vanilla extract and stir to combine.
Press half of the dough into the prepared baking dish (we'll use the rest of the dough for the crumble topping.)
Bake for 12-15 minutes, or until the top turns a light golden color.
Spread all the cherry pie filling on top of the partially baked crust in an even layer. Then crumble the remaining dough mixture until most of the top is covered. It won't completely cover the pie filling.
Bake for another 30-40 minutes, or until the top turns a light golden color.
While the bars are baking, mix together the powdered sugar, milk and the vanilla extract. Start with one tablespoon of milk and add more as needed.
Let the bars cool for 20 minutes. Drizzle the icing on top then allow to set for another 15 minutes. Then slice and serve!
Notes
You can use any pie filling for this: blueberry, peach, strawberry, and apple all work perfectly with this recipe.
If you want to make your own homemade pie filling you can do that as well. Make sure the pie filling is thick and sturdy enough (not wet) otherwise these bars will not turn out.
This makes a large pan already, but you can absolutely double this if you plan on serving more people or are doing a bake sale, etc.
These are great warm or cold but they do need to cool slightly before cutting so they will set up and also for the glaze to not melt off the bars.
A jelly roll baking dish is approximately 10x15-inches and are one inch high. For thinner bars use a half sheet pan which is approximately 18x13-inches and 1 inch high.