11 ounces butter, plus more for the pan (2 3/4 sticks)
1 cup sugar
2 cups all-purpose flour, plus more for the dough
2 cups almond flour
¼ teaspoon kosher salt
½ cup dried cherries
2 cups chunky cherry preserves
½ cup sliced blanched almonds, lightly toasted
Standing electric mixer with the paddle attachment;
To make the tart dough, cream the butter and sugar in the mixer bowl on medium-high speed until light and fluffy. Add the flours and salt to the bowl, and beat on low speed just until the dry ingredients are incorporated and a cohesive dough forms.
Scrape the dough out of the bowl onto a work surface, and knead a few times, until it comes together in a ball. Divide into two pieces (a larger piece of 2/3 of the dough, and a small piece of 1/3 of the dough). Press both pieces into flat rectangles, and wrap them well in plastic wrap. Refrigerate for 2 hours (or for a day) before rolling; freeze for longer keeping.
When you are ready to bake the tart, arrange a rack in the center of the oven and heat to 350 degrees. Butter the bottom and sides of a 10x15 jelly-roll baking pan. In a small bowl, cover the dried cherries with warm water (or rum or liqueur); let them soak and soften.
Place the larger piece of dough between two sheets of parchment, and roll it out to a rectangle a bit larger than the jelly-roll pan. Peel off the top layer of parchment, and invert the dough so it lies centered in the pan, then peel off the second parchment sheet. Gently press and push the dough into the pan to form a smooth, intact crust, even on the bottom, and slightly thicker against the sides of the pan. Scrape off excess dough so the crust is flush with the pan sides, and save all the scraps. (If the crust tears or is too thin in spots, patch with the extra dough.)
For the tart filling, scrape all the cherry preserves into a bowl, drain the rehydrated cherries, and stir into the preserves. Spread all the filling in the crust, covering the bottom evenly. Roll the smaller piece of dough between the parchment sheets to a round or oblong sheet (about as thick as you rolled the larger piece of dough). Peel off the top layer of parchment; to make a decorative top crust you can cut out circles or other shapes with floured cookie cutters or use a pastry wheel to cut diamonds or lattice strips). If you are short on top crust dough gather and reroll all the dough scraps to make more shapes, and lay them all over the tart, in any pattern you like, with the cherry filling peeking through. Sprinkle the sliced almonds evenly over the top of the tart.
Set the tart in the oven, and bake about 50 minutes, rotating the pan halfway through the baking time, or until the crust is deep golden brown and the filling is bubbling.
Let the tart cool tart completely on a wire rack. Cut in pieces of any size, and serve on individual dessert plates, or arrange the pieces on a serving platter for a buffet or picnic. Dust them with confectioners' sugar, or accompany with whipped cream, ice cream, or zabaglione.