Creating the Autumn Apple & Pumpkin Galette is simple when you follow these steps:

1. Make the Dough: In a mixing bowl, combine the flour, sugar, and salt. Add the cold butter and mix until the mixture resembles coarse crumbs. Gradually add ice water, one tablespoon at a time, mixing until the dough comes together. Wrap in plastic wrap and refrigerate for 30 minutes.

2. Prepare the Filling: In a large bowl, combine the sliced apples, pumpkin puree, brown sugar, cinnamon, nutmeg, ginger, and lemon juice. Toss until the apples are well-coated and set aside.

3. Preheat the Oven: Preheat your oven to 375°F (190°C).

4. Roll Out the Dough: On a lightly floured surface, roll out the chilled dough into a 12-inch circle. Transfer the dough to a parchment-lined baking sheet.

5. Assemble the Galette: Spoon the apple and pumpkin filling onto the center of the dough, leaving a 2-inch border around the edges. Fold the edges of the dough over the filling, pleating as necessary to create a rustic look.

6. Prepare the Egg Wash: In a small bowl, whisk together the egg and milk. Brush the egg wash over the crust and sprinkle coarse sugar on top.

7. Bake: Place the galette in the preheated oven and bake for 40-45 minutes or until the crust is golden brown and the filling is bubbly.

8. Cool: Remove the galette from the oven and allow it to cool on the baking sheet for 15-20 minutes before slicing.

9. Serve: Enjoy your Autumn Apple & Pumpkin Galette warm or at room temperature, with a scoop of vanilla ice cream or a dollop of whipped cream if desired.