In the bowl of a standing mixer (or a large bowl if you are using a pastry cutter or a fork instead) mix flour and salt together.
With your mixer on low (or with your fork or pastry cutter), work the cold butter into the flour, a little at a time, until the mixture resembles coarse crumbs.
Add in ice water, 1-2 Tbsp at a time, until the dough just comes together.
Turn dough out onto a floured surface, split in half and form each into a ball (or a flat disc).
Wrap in plastic wrap and refrigerate at least 30 minutes.
When you’re ready to make your peach slab pie, preheat the oven to 425 degrees.
In a large bowl, mix peaches, granulated sugar, brown sugar, all purpose flour, cornstarch, vanilla extract, lemon zest, lemon juice, ground cinnamon, ground ginger, ground all spice and ground nutmeg together. Set aside.
On a floured surface, roll one ball of dough into a large rectangle, rolling until it’s about a 1-8”-1/4” thick.
Transfer the dough to your 9x13” rimmed baking sheet (1/4 sheet pan). I like to transfer the dough by loosely rolling the dough back around my rolling pin and then unrolling the dough over the baking sheet.
Gently press the dough into the baking sheet. Remove any excess pie dough from the edges of the pie (leaving about 1/2” of overhang, if possible).
Pour the peach filling into the pie dough.
Dot the filling with the 2 Tbsp of cubed, cold butter.
Roll out the second ball of dough and place on top of the pie, using a fork or your fingers to crimp the edges together. Using a knife, cut a slits into the pie for ventilation.
Brush with egg wash.
Alternatively, if making a lattice crust, after rolling out the dough into a rectangle, cut the dough into about 1/2”-3/4” strips (you’ll need about 11 strips; 5 strips need to be long; 6 need to be shorter).
Place the 5 long strips evenly length-wise on the pie. Weave the remaining 6 strips in and out width-wise on the pie. Crimp the edges of the pie and brush with egg wash.
Bake pie at 425 degrees for 15 minutes. Reduce the temperature to 375 degrees and bake for a remaining 40-50 minutes, or until the crust is golden brown and the filling is bubbling. (If the crust is browning too soon, you can tent a piece of foil on top of the pie and continue baking.)
Allow the pie to cool (the longer the pie cools, the more the pie filling will thicken up) before serving. Or, once the pie has reached room temperature, you can place it in the fridge and serve it chilled.
Pie can be served warm, at room temp or cold. Store all leftovers in the fridge.
Top with whipped cream or ice cream, if desired.
Enjoy!