Creating the Nectarine Raspberry Galette is simple if you follow these steps:

1. Make the Dough: In a large bowl, combine flour, granulated sugar, and salt. Add the chilled butter and mix until the mixture resembles coarse crumbs.
2. Add Water: Gradually add ice water, one tablespoon at a time, mixing until the dough comes together. Form into a disk, wrap in plastic wrap, and refrigerate for at least 30 minutes.
3. Prepare the Filling: In a medium bowl, combine the sliced nectarines, raspberries, brown sugar, cornstarch, and vanilla extract. Stir gently to combine and set aside.
4. Preheat the Oven: Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper.
5. Roll Out the Dough: On a lightly floured surface, roll out the chilled dough into a 12-inch circle, about ¼ inch thick.
6. Transfer to Baking Sheet: Carefully transfer the rolled-out dough to the prepared baking sheet.
7. Add the Filling: Spoon the fruit filling into the center of the dough, leaving about a 2-inch border.
8. Fold the Edges: Gently fold the edges of the dough over the filling, pleating as you go to create a rustic look.
9. Brush with Egg: Brush the exposed edges of the dough with the beaten egg and sprinkle coarse sugar on top.
10. Bake: Bake in the preheated oven for 30-35 minutes, or until the crust is golden brown and the filling is bubbly.
11. Cool: Remove from the oven and let cool for 15-20 minutes before serving.

By following these steps, you’ll create a stunning and delicious Nectarine Raspberry Galette that everyone will love!