Peel, pit, and slice the peaches into 1/2-inch thick wedges, setting them aside in a bowl. Preheat your oven to 400°F so it reaches temperature while you prepare the filling. This allows you to work without rushing once the filling is ready to bake.

In a medium saucepan, whisk together the granulated sugar, water, cornstarch, and lemon juice until the cornstarch is fully dissolved with no lumps. This creates a smooth slurry that will thicken evenly as it cooks. I find whisking thoroughly here prevents any starchy lumps from forming in your final filling.

Bring the mixture to a boil over medium heat, stirring frequently, and cook for 2-3 minutes until it thickens and turns glossy and translucent. Once thickened, remove from heat and immediately stir in the vanilla, ground cinnamon, and salt. These warm spices bloom beautifully when added to the hot liquid, infusing the filling with aromatic warmth.

Gently fold the sliced peaches from Step 1 into the thickened mixture until evenly coated. Let the filling cool to room temperature, stirring occasionally—this takes about 15-20 minutes. Cooling is essential because adding warm filling to a cold crust can create uneven baking and a soggy bottom crust.

Remove the pie crusts from the refrigerator. Pour the cooled peach filling from Step 4 into one crust, spreading it evenly. Place the second crust on top and seal the edges by pressing with a fork or crimping with your fingers. Cut 3-4 slits in the top crust to allow steam to escape during baking, which prevents a soggy filling and helps the crust bake evenly.

Place the assembled pie on a baking sheet (to catch any drips) and bake in the preheated 400°F oven for 40-45 minutes until the crust is golden brown and the filling begins to bubble slightly through the slits. Remove from the oven and let cool on a wire rack for at least 2-3 hours before slicing. This cooling time allows the filling to set properly so it slices cleanly rather than running.