In a large bowl, whisk together the all-purpose flour, granulated sugar, and salt.

Add the cold, cubed unsalted butter. Use a pastry cutter or a food processor to cut the butter into the flour until the mixture resembles coarse crumbs, with some pea-sized bits remaining.

Gradually mix in 3 to 4 tablespoons of ice water until the dough starts to come together. Don’t overwork it.

Form the dough into a disk, wrap it in plastic, and chill for at least 30 minutes (up to 2 hours).

While the dough chills, beat the softened butter with the powdered sugar until creamy.

Then, mix in the almond flour, large egg, vanilla extract, and almond extract if using. Set the almond cream aside.

In a separate bowl, combine the pitted sour cherries, granulated sugar, cornstarch, and lemon juice.

Toss gently to coat the cherries evenly.

Lightly flour your work surface and rolling pin.

Roll the chilled dough into a rough 12-inch circle that’s about ⅜ inch thick.

Transfer this dough to a parchment-lined baking sheet.

Spread the almond cream evenly over the center of the dough, leaving a 2-inch border free.

Spoon the cherry mixture over the almond cream, distributing evenly but not piling too high.

Fold the dough edges up over the filling, pleating gently to contain the fruit but leaving the center exposed.

Brush the crust edges with the egg wash to get a golden finish.

Sprinkle sliced almonds over the cherries and dust the crust with turbinado sugar.

Preheat the oven to 375°F (190°C).

Bake the galette for 40-45 minutes until the crust is golden and the cherries are bubbly. Tent with foil if the edges brown too quickly.

Let the galette cool on a rack for at least 20 minutes before slicing.

Serve warm or at room temperature, optionally with vanilla ice cream or whipped cream.