Recipe courtesy of Alisha Falkenstein of II Solito in Portland.
Combine dry ingredients and cut in the cold butter using your hands, until the mixture resembles a coarse cornmeal. Slowly add cold water just until dough starts to form. You may not need all of the water. Keep mixing until dough is just combined, but do not overmix as it will lead to a tough crust. Wrap in plastic wrap and refrigerate for at least an hour, or overnight.
In a stand mixer with the paddle attachment, cream butter, sugar, almond our and lemon zest together. Slowly add in egg, vanilla extract and almond extract. Scrape the bottom of the bowl and mix until smooth.
Combine all ingredients, and toss together. Be sure the grapes are evenly covered.
Preheat oven to 375 degrees. If the pie dough was refrigerated overnight, let it sit out to soften just enough to easily roll out. Roll dough on a floured surface into as much of a circle as possible. Roll dough so it is 1⁄4-inch thick, then cut dough to make into an even circle. Place rolled dough on a parchment lined sheet pan.
Spread frangipane on prepared dough, being sure to leave a 1-inch border on the outside edge. Evenly arrange grape mixture on top of the frangipane. Fold dough over grapes, creating about a 1-inch wide crust. Brush with egg wash or heavy cream, sprinkle with turbinado or granulated sugar.
Bake at 375 degrees for 15 minutes, then reduce temperature to 350 degrees and bake for another 10 minutes or until crust is golden brown and the grapes begin to split. Let cool slightly, then serve with vanilla bean ice cream or whipped cream.