This slab pie is easy to make and you can substitute in any fruit. You could also turn this recipe into a galette, which is a circle out of the pan pie, where the center of the pie is uncovered, just like this slab pie.
In a medium bowl, mix the flour, powdered sugar, baking powder, and salt.
Using your fingers, cut in the butter until the mixture is crumbly.
Add the egg yolks and milk and mix until the dough is just combined.
Gather the dough into a ball and wrap with plastic wrap and refrigerate for 1 hour or up to 3 days.
Combine the sliced peaches, diced cherries, 2 tbsp sugar and cinnamon in a mixing bowl. Set aside.
Preheat the oven to 350ºF. Liberally spray the pan you’re using with non-stick cooking spray. I recommend using a 10.5 x 15.5 jelly roll pan or something smaller in size if you don’t have that exact size.
Using extra flour, begin to roll the dough into a large rectangle, large enough to fit the pan you’re using and make sure you have some extra dough on the sides to fold the dough over.
Transfer the dough into the baking sheet.
Evenly distribute the fruit all over the pan. Fold the extra dough in towards the middle.
Brush the edges of the dough with the egg wash (whisk the egg and water). Sprinkle 2 tbsp of sugar around the edges.
Bake for 35-40 minutes or until the crust is golden brown and the juices are bubbling.