To make the dough:
Beat the butter and confectioners’ sugar in a heavy-duty mixer with the paddle attachment until mixed together. Add the ground almonds, egg, and vanilla, and then the flour and salt. Mix until just combined. Transfer the dough to a lightly floured surface, shape into two disks, and wrap both in plastic. Refrigerate one disk for at least 1 hour and up to 3 days; freeze the other for future use.
To assemble and bake:
Heat the oven to 400°F. Remove the dough from the refrigerator. On a lightly floured work surface, roll it into a round 1/8-inch thick. (If the dough crumbles, it’s too cold; gather it into a ball, knead a few turns, and roll again.)
Transfer the dough by rolling it onto the rolling pin and then unrolling it over a 9- or 9-1/2-inch fluted tart pan that’s 1 inch deep and has a removable bottom. Gently ease the dough into the bottom and up the sides of the pan. To remove excess dough, run the rolling pin over the top of the edges to cut it off. Put the pan on a baking sheet, line the dough with parchment, and fill it with pie weights, dried beans, or rice. Bake it in the middle of the oven until the sides are set, 10 to 15 minutes. Carefully remove the weights and parchment, return the shell to the oven, and bake until the bottom is set and the crust is light brown, another 7 minutes.
Unroll the dough over the tart pan...
...then press with the rolling pin to give the tart clean edges. Excess dough can be used to patch any holes, if needed.
Spread the cherries in the bottom of the tart crust in one layer (you can do this while the tart is still hot). Whisk together the cream, sugar, and eggs and carefully pour the mixture over the cherries until the custard comes just to the top of the pan; you may have an extra tablespoon or so of custard remaining. Sprinkle the almonds on top. Return the tart to the oven and bake until the top is brown and the cherries are bubbling, about 40 minutes. Let the tart cool until you can remove it from the pan.
A sweet, creamy custard surrounds whole sweet cherries. Pay attention as you pour so that you don't overfill the crust.