To make the Shortbread Tart Crust

1. In the bowl of a food processor, combine the almonds and sugar and pulse until the almonds are finely ground. Scrape the sides and bottom food processor bowl before adding the next ingredients.
2. Add the flour and salt and pulse a few times to mix. Then add the butter and pulse repeatedly until the butter is fully blended into the flour. Add the egg yolk and vanilla and pulse again until the mixture forms into a ball of dough.
3. Carefully remove the blade from the bowl, then gather the dough and shape into a thick disk. Wrap in plastic and refrigerate for at least one hour (or see note above for longer chilling options).
4. Prepare the tart for baking (this step should be done the day before serving) by first taking the dough out of the refrigerator and allowing it to come up to room temperature for about 20 minutes. Flour a flat work surface and roll the dough into a round 13-inch circle, adding more flour under and on top of the dough as you roll, if necessary to avoid sticking.
5. Fold the circle of dough in half and slide your hands under it, palms up. Transfer the dough to the tart pan – lining up the fold with the center diameter of the pan. Unfold the dough and gently fit it into the pan – flat on the bottom and pressing it up the sides of the pan. If the dough tears, just press it back together with your fingers.
6. Trim away any excess dough at the rim of the tart pan (you can use a knife or you can roll over the top of the pan with a rolling pin). Press the top edge up a bit if it was pushed down from trimming.
7. Cover the tart pan with plastic wrap and refrigerate for several hours or overnight before baking.

Note that the tart shell and the almond crumb topping will be baked at the same time. When you are ready to bake the crust, set your rack in the upper and lower thirds of your oven and preheat it to 350 degrees.

To prepare the Almond Crumb Topping

1. While the oven is preheating, line a baking sheet with foil and set aside.
2. In a mixing bowl, combine the flour, sugar, baking powder, cinnamon and salt and evenly mix together. Stir the almonds. Using a rubber spatula, stir in the melted butter and evenly mix again. Allow the mixture to cool for a few minutes – then, using your fingertips, break the mixture into coarse crumbs.
3. Scatter the crumbs evenly on the prepared baking sheet.
4. Remove the tart shell from the refrigerator. Line the crust with a circle of parchment paper and then weigh down with the pie weights or dry beans (this step will prevent the tart shell from puffing up as it bakes).
5. Place the tart shell on the bottom rack in the oven and the crumb mixture on the top rack. Bake both for 10 minutes.
6. After 10 minutes, remove the parchment and the weights from the tart shell (careful – they will be hot!). Then move the crumbs to the bottom rack and put the tart shell in the oven on the top rack.
7. Bake the crumbs for 10-15 minutes more until golden brown. At the same time, bake the tart shell – for 15 to 20 minutes or until golden brown. Cool the shell and the crumb mixture completely on cooling racks.

To Prepare the Peaches & Cream Filling

1. While the shell and the crumbs are cooling, prepare the cream filling.
2. In a bowl, combine the peaches and the 1 tablespoon of confectioner’s sugar, stirring to mix well. If your peaches are very tart, add additional sugar as needed. Set aside.
3. In the bowl of a stand mixer fitted with a paddle attachment, cream the softened cream cheese until very smooth. Add the 1¼ cups confectioner’s sugar, lemon zest, and vanilla and beat on high until light and fluffy, about 1 minute.

To Assemble the Tart

1. A few hours before serving, evenly spread half of the cream cheese mixture into the cooled tart shell. Spoon the peaches evenly over the filling. Then spread the remaining cream cheese mixture evenly over the peaches. Sprinkle the cooled almond crumb topping over the top of the filled shell – breaking apart any large crumbs that may be formed during baking with your fingers.
2. Serve this tart at room temperature. To serve, unmold the tart from the pan and cut into wedges.