• Place the flour, salt and sugar into the bowl of a stand mixer with the dough attachment. Add the pieces of butter and mix until the mixture starts to resemble small peas or breadcrumbs. Add the ice water one tablespoon at a time, until the dough is moist enough to come together.
• Knead the dough into a ball. Flatten into a disc, wrap in cling wrap, and place in the refrigerator where the dough will chill for 30 minutes.

Crumb topping

• Combine all the crumb ingredients and set aside.

Apple filling:

• Peel and seed the apples and cut into slices. Combine the sugar, flour, cinnamon, and salt. Toss the apples in the mixture.
• Preheat the oven to 375 F.
• To form the galette, roll out the dough into a large circle, measuring 14-15 inches, on a lightly floured piece of parchment paper. Brush the apricot jam over the center of the circle, leaving a 3 to 4 inch border. Place 3/4 of the crumb over the jam, followed by the apple slices. Sprinkle the remaining crumb over the apples. Use the parchment paper to fold the dough over the apples until your galette is shaped. Place onto a baking sheet and brush the dough with the beaten egg yolk.
• Bake at 375. After 25 minutes, remove from the oven and cover with foil, and bake for another 30 minutes longer.