To make the galette dough, place the flour, sugar, and salt in the bowl of a food processor. Pulse a few times to blend. Add the cold butter pieces and pulse 8 to 10 times, until the butter is pea-size. With the machine running, gradually add 4 tablespoons of the ice-cold water, one tablespoon at a time. If the dough hasn’t formed a ball by this point, add the remaining tablespoon of water and process until the dough comes together. Transfer the dough to a flat surface, shape it into a 5-inch disk, wrap it in plastic wrap and refrigerate for 30 to 60 minutes (and up to 3 days). Pull the dough from the fridge 10 minutes before rolling out.

While the dough is chilling, prep the peaches. In a large bowl, combine the peaches, lemon juice, cornstarch, vanilla, and salt. Toss to coat.

Preheat the oven to 375 degrees. Line a large baking sheet with parchment paper.

Working on a lightly floured surface (or large piece of parchment paper), roll the dough into a 12-inch round, about 1/8-inch thick. If necessary, mend any cracks or tears by pressing them back together with your fingers.

Carefully transfer the dough to the parchment paper on the baking sheet (if desired, use your rolling pin to roll up the dough so you can transfer it with ease). If you rolled out your dough on parchment paper, simply transfer the paper to the baking sheet.

Place a 9-inch pie pan in the center of the dough and press down gently to create a slight indentation - this step is optional, but it helps guide you when adding the peach filling.

Arrange the peaches in the center of the dough (using the indentation as a guide). For a decorative presentation, start arranging slices around the outside edge of the indentation – or 2-inches from the outer edge of the dough – and work your way in, slightly overlapping the slices as you go.

Fold up the edges of the dough, partially covering the filling, and overlapping/folding the dough as needed as you work your way around the circle.

Brush the heavy cream (or egg) all over the dough. Sprinkle the peaches and crust with the granulated sugar. Refrigerate for 10 minutes.

Transfer the baking sheet to the oven and bake for 30 to 40 minutes, until the crust is golden brown, and the filling is soft and bubbly. Transfer the galette (still on the parchment paper) to a wire rack to cool (the galette will be soft, so be careful when transferring).

Once cooled, warm the apricot preserves in a small saucepan or in the microwave until thin enough to brush over the fruit. Brush the preserves all over the peaches.

Slice the galette into wedges and serve with vanilla ice cream if desired.