Cut the butter into small cubes and return them to the fridge (the smaller the cubes, the flakier the crust). Measure out 1/4 cup plus 3 tablespoons water and place in the fridge to keep it cold until you’re ready for it.

Make the dough: In the bowl of a stand mixer fitted with the paddle attachment, add 1 2/3 cups plus 3 tablespoons flour and 1 teaspoon sugar. Turn the mixer on low for 2 to 3 rotations to combine the dry ingredients.

Add the cold, cubed butter to the flour mixture. Turn the mixer on low and slowly start to incorporate the ingredients. Gradually turn the mixer to medium speed. Once the butter mixture looks like wet sand, immediately add all the cold water. As soon as the dough comes together, stop the mixer. Do not over mix.

Divide the dough into two portions, one should be almost double the size of the other. I prefer to weigh them, the large one should weigh 312 grams and the small should weigh 170 grams. Form them both into disks and wrap separately in plastic wrap. Allow to rest in the fridge for at least 6 hours or overnight.

When you’re ready to assemble the pie, preheat the oven to 350 F. Whisk the egg, then add 1 tablespoon of egg into a separate bowl and mix with 1 tablespoon of water to create an egg wash. Set aside. (Store the remaining egg in an airtight container in the fridge, and make it for breakfast!)

Make the filling: In a large bowl, whisk together the remaining 1/2 cup sugar, remaining 3 tablespoons flour, cornstarch, and salt. Add the fruit and fold with a spatula to coat the berries completely. Set aside.

Assemble the pie: Grease a pie pan well with butter. (Tip: Using an aluminum pie pan will give you the best results. If you use ceramic or glass, you will have to bake longer to prevent a soggy bottom crust.) Remove the pie dough from the fridge. Remove the plastic wrap and place on a floured surface. First, roll out the large disk to 1/4-inch thick and about 11 inches in diameter. Transfer the rolled-out dough to the pie pan and press lightly to form against the pan. It should be large enough that the dough folds over the edge by about an inch. Roll out the smaller disk to 1/4-inch thick and about 9 inches in diameter.

Add the filling into the pie pan and spread evenly. Gently place the remaining dough round on top. Crimp the top and bottom crusts together, and then roll the crust under twice to create an edge that seals the filling in. Flute the edges by using your thumb and index finger of your right hand to pinch the rolled edge of dough, and push the index finger of your left hand into it to create the “flute.” Continue around the entire pie.

Using a pastry brush, brush the dough with the egg wash. Make a vent in the top of the pie using a sharp knife. I like to make four little vents. Bake for 1 hour and 15 minutes, or until golden brown. Store at room temperature for up to 3 days.

High Altitude – Bake at 350 F for 1 hour, or until golden brown.