Ingredients:

For the levain:

20g sourdough starter or sourdough discard

40g flour

60g water

For the final dough:

2/3 cup (120g) levain

1 scant cup (120g) Sequoia flour

1 scant cup (120g) Organic Edison flour

5g baking powder

½ cup (120g) unsalted or cultured butter, cold, cubed

For the caramel sauce:

1 cup (230g) apple cider, filtered or unfiltered

1⅛ cup (230g) cane sugar

1½ tablespoon (30g) unsalted or cultured butter

¾ teaspoon (3g) salt

¾ cup (175g) heavy cream

For the filling:

3½ cups (670g) cider caramel sauce, divided

3 medium fuji apples, cored and sliced

1 tablespoon (20g) unsalted or cultured butter, cold, cubed

1 tablespoon (20g) cane sugar

½ teaspoon cinnamon

Sugar + cinnamon mixture for sprinkling

For topping and serving:

1 egg, slightly beaten with 1 tablespoon cold water, for egg wash

Optional: instead of an egg wash, 1-2 tablespoons of heavy cream can be used

Demerara or crystal sugar, to taste

Vanilla ice cream

Toasted sliced almonds

Instructions:

To make the levain:

1. A couple of hours before you're ready to mix the dough, prepare the levain: feed your mature sourdough starter or discard with flour and water. Let sit at room temperature until bubbly, fragrant, and doubled in size, about 4 hours.

To make the cider caramel sauce:

1. While the levain is ripening, prepare the cider caramel sauce: in a medium-size, thick-bottomed saucepan, combine the apple cider, sugar, butter, and salt.
2. Bring to boil on medium heat, immediately turn down the flame and simmer until the mixture has the consistency of maple syrup, about 15-20 minutes, stirring regularly.
3. Once the syrup is nice and thick, slowly add the heavy cream and continue simmering until the mixture is reduced again and is thick enough to coat the back of the spoon.
4. Let the caramel sauce cool at room temperature for about 1-1.5 hours. It will have a loose, syrupy consistency.

To make the final dough:

1. While the caramel is cooling, prepare the final dough: in a large, chilled bowl, stir together the two flours and baking powder.
2. Sprinkle the cold cubed butter over the flour and cut it in using a pastry cutter. Make sure to leave some pea-sized bits of butter to create a nice, flaky texture.
3. Add the levain and stir with a fork to combine, just until the dough holds together.
4. Turn the dough onto a well-floured surface. Shape it into a disk, wrap in plastic wrap and refrigerate for 1 hour.

To assemble the galette:

1. Line a pastry sheet with parchment paper and set aside.
2. Take the dough of the refrigerator and, working on a well-floured surface, roll it into a circle about 14-15" in diameter.
3. Drape the dough over the rolling pin and gently transfer it onto the parchment-lined baking sheet.
4. Evenly spread about ¾ of the cooled caramel sauce over the dough, leaving a 2-3" border around the perimeter. Reserve the remaining caramel sauce.
5. Arrange the apple slices in overlapping concentric circles over the caramel sauce, again avoiding the 2-3" border, until you've used up all of the apples.
6. Fold the 2-3" edges of the dough up over the apples, in a rustic, free-form style, creating pleats around the circle as you go.
7. Sprinkle the apples with the sugar-cinnamon mixture, to taste.
8. Dot the apples with cubed butter.
9. Wash the pastry with the egg wash or cream and sprinkle with demerara or crystal sugar.
10. Refrigerate the assembled galette for 30-60 minutes.

To bake the galette:

1. Preheat the oven to 375°F, with the baking rack positioned in the center of the oven.
2. Take the galette out of the refrigerator and place it in the preheated oven.
3. Bake for 25 minutes.
4. After 25 minutes have passed, lower the oven temperature to 350°F, rotate the baking sheet 180° to ensure even baking, and bake for another 20 minutes, until nice and golden.
5. Take out of the oven and let cool slightly.
6. Serve warm, topped with vanilla ice cream, reserved cider caramel, and toasted sliced almonds.