10 tbsp unsalted butter – cold, cut into small cubes
4 tbsp ice water
1.5 pounds apples – peeled, cored, thinly sliced
1 tbsp lemon juice
0.33 cup granulated sugar
0.25 cup almond flour
2 tbsp unsalted butter – cut into small dice (for dotting)
1 large egg – beaten (for egg wash)
2 tbsp apricot jam – warmed for glazing
Instructions
Make the dough: In a large bowl, whisk the all-purpose flour, 1 tbsp granulated sugar, and fine salt. Cut in the 10 tbsp cold unsalted butter with a pastry cutter or fingertips until pea-sized bits remain.
Sprinkle in 3–5 tbsp ice water, tossing with a fork just until the dough holds together when pressed. Gather into a disk, wrap, and chill until firm, about 1 hour.
Preheat the oven to 400°F (200°C). Line a rimmed baking sheet with parchment paper.
Prepare the apples: In a bowl, toss the sliced apples with the lemon juice and 0.33 cup granulated sugar until coated.
On a sheet of parchment, roll the chilled dough into a 12-inch round about 1/8 inch thick. Slide the parchment and dough onto the lined baking sheet.
Sprinkle the almond flour evenly over the center, leaving a 2-inch border clear around the edge.
Arrange the apples over the almond flour in overlapping concentric circles. Pour any juices from the bowl over the apples and dot with the 2 tbsp diced unsalted butter.
Fold the bare dough border up over the fruit, pleating as you go to form a rustic edge. Chill the assembled galette for 10 minutes to help it hold its shape.
Brush the crust with the beaten egg. Bake until the crust is deep golden and the apples are tender and bubbling at the edges, 35–45 minutes.
Warm the apricot jam until fluid, then brush it over the apples. Let the galette cool for 10 minutes before slicing and serving.