Place the dough circle on a parchment paper-lined baking sheet, cover, and chill in the refrigerator until firm, about 10 minutes. Meanwhile, prepare the frangipane.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar until creamy, about 3 minutes. Add 1 of the eggs and almond extract and mix well. Stop the machine and use a rubber spatula to scrape down the sides and bottom of the bowl. Add the almond flour, tapioca starch, and sea salt and beat until fully incorporated. (If not using the frangipane right away, store, covered, in the refrigerator for up to 1 week.)
Remove the dough from the refrigerator and spread the frangipane in the center of the dough circle, leaving a 2-inch border.
Taste the fruit you are using for sweetness to determine how much sugar you want to use. Scatter the fruit evenly over the frangipane, then sprinkle with the sugar.
Fold in the sides of the dough to cover the fruit partially, making sure not to create any valleys where the fruit juice can run out. Refrigerate until firm, about 15 minutes.
While the galette chills, arrange a rack in the middle of the oven and heat the oven to 425°F. If you have a baking stone, set it on the floor of the oven to preheat.
Whisk together the remaining egg with a pinch of salt. Brush the egg wash over the pastry edges, then sprinkle with the 1 tablespoon sugar.
Bake the galette on the baking stone or directly on the floor of the oven for 20 minutes. Reduce the oven temperature to 375°F, move the baking sheet to the middle rack, and continue baking until the pastry has a nice, dark golden brown color and the fruit is bubbling, 25 to 30 minutes more.
Remove from the oven and serve hot, or let cool on a wire rack and serve warm or at room temperature.
In the bowl of a food processor fitted with a metal blade, combine all the dry ingredients and blend to mix well.
Add the cream cheese and butter and pulse about 15 times, then let the food processor run just until the dough begins to come together in a ball but is not completely smooth, about 20 seconds. You should still be able to see some butter and cream cheese chunks.
Divide the dough into 2 equal balls and shape each ball into a disk about 1 inch / 2.5cm thick. Wrap well in plastic wrap and chill for at least 2 hours or overnight.