Embrace summer with a Cherry Berry Peach Pie! This all-butter, lattice top pie crust is filled with summer favorites like sweet & sour cherries, strawberries, blueberries, and ripe peaches.
Combine flour, sugar, and salt in the bowl of a food processor. Pulse briefly until combined.
Add butter and pulse just until the butter is incorporated throughout the mixture in small crumbs.
Gradually add the cold buttermilk, pulsing briefly until the dough begins to form large clumps.
Remove dough from the food processor and knead just until it comes together. Divide the dough in half and form into two discs. Wrap each disc tightly in plastic wrap and chill the dough for at least 1 hour.
Once dough is chilled, combine the peaches, cherries, strawberries and blueberries in a large bowl. Toss gently to combine.
In a small bowl, whisk together both sugars, cornstarch, and salt. Add the dry ingredients to the fruit and toss gently to combine. Set aside.
Preheat the oven to 400 degrees Fahrenheit.
On a large, lightly floured surface, use a rolling pin to roll out one of the discs of pie dough. Form a large circle of dough, about 12" in diameter. Lay the pie crust in the bottom of a 9.5" pie plate and trim the edges, leaving an extra inch of dough all the way around the rim of the pie dish (this will be used to seal the edges at the end). Place the bottom crust in the fridge while you roll out the second disc of pie dough and slice it into long strips for a lattice design.
Spoon the fruit filling into the bottom crust, leaving behind excess juices so the pie doesn't get too soggy. Arrange the strips of pie dough on top in a lattice design (see instructions in post), then seal & crimp the edges.
In a small bowl, whisk together the egg, water, and salt. Use a pastry brush to coat the pie crust with a thin layer of egg wash. Sprinkle with sugar.
Place the pie on the middle rack of the oven. Place a large baking sheet on the bottom rack, to catch any drips. Bake the pie at 400 degrees for 20 minutes, then reduce the temperature to 375 degrees and bake for an additional 35-40 minutes. Keep an eye on the pie & cover it with a foil shield if it is browning too quickly.
Remove the pie from the oven and let cool completely on a wire rack before serving, to help the pie filling set.
*The filling recipe is adapted from Wood & Spoon's Peach Berry Pie.