Preheat the oven to 350 degrees.
In a bowl, whisk together the 1 ½ cups all purpose flour, ½ tbsp granulated sugar, and 2 tsp salt. Add the cubed ¾ cup unsalted butter and work into the dough with a pastry cutter, fork, or just your fingers until pea sized pieces of butter form in the flour mixture.
½ cup granulated sugar, 2 tsp salt, 1 ½ cups all purpose flour, ¾ cup unsalted butter
Add the ½ cup ice water and continue to work the dough for about a minute until it holds together when pressed into a ball, but chunks of butter are still visible.
½ cup ice water
Flatten the dough into a 2 inch thick circle and wrap in plastic wrap. Chill in the fridge for at least 1 hour.
Meanwhile, add the melted ¾ cup unsalted butter, ¼ cup brown sugar, ½ cup granulated sugar, 2 eggs, 1 ¾ cup almond flour, and 2 tsp almond extract to a food processor. Blend for about 1 minute until the mixture is smooth and fully incorporated. It will still be somewhat grainy from the almond flour. Transfer the frangipane to a bowl and seal tightly with plastic wrap. Chill for at least one hour.
¾ cup unsalted butter, ¼ cup brown sugar, ½ cup granulated sugar, 1 ¾ cup almond flour, 2 tsp almond extract, 2 eggs
Whisk together the ½ cup brown sugar, ½ cup granulated sugar, ½ cup all purpose flour, 1 tbsp cinnamon, ½ tsp nutmeg, and 2 tsp salt in a large bowl. Add the sliced 3 honey crisp apples, 4 bartlett pears, and 4 black plums to the mixture and stir until all of the fruit is fully coated.
3 honey crisp apples, 4 bartlett pears, 4 black plums, ½ cup brown sugar, ½ cup all purpose flour, 1 tbsp cinnamon, ½ tsp nutmeg, ½ tbsp granulated sugar, 2 tsp salt
Remove the dough from the fridge and place on a floured surface. Use a rolling pin to roll the dough into a ¼ inch thick round.
Place the dough to a springform pan that is 10” in diameter and about 3” deep. Press the dough into the bottom and sides so a flat, even crust forms. Use a fork to poke about 20 holes in the bottom and sides of the dough.
Spread the frangipane in an even layer on top of the unbaked dough.
Layer the pears, apples, and plums in a circular fashion, slighting overlapping each slice. Repeat this circle pattern in layers until all of the fruit is used or the pan is full to the top. Pour the excess liquid in the bottom of the bowl over the tart.
Cover the pan tightly with aluminum foil and place the tart in the oven. Bake for 1 hour. Remove the foil and raise the temperature to 400 degrees. Bake for an additional 20 minutes. Until the crust is golden brown and the filling is bubbly.
Let the tart sit in the pan at room temperature for at least 1 hour before removing from the pan and serving.