Step 1Using the side of your knife or your fingers, lightly crush each cherry, split it in half, and remove the pit. Place the cherry halves (about 4 cups, or 1 pound 7 ounces) in a bowl and discard the pits. (You can also use a cherry pitter, but I prefer the hand-torn look. Do what you prefer.)
Step 2Grease a 9-inch cake pan with some butter, line the bottom with a round of parchment paper, then grease the paper.
Step 3Heat a large skillet over medium-high heat. Add the cherries, sugar, liqueur (if using) and ½ teaspoon salt, and cook, tossing occasionally, until the cherries give up a lot of their liquid, are half-tender, and are bubbling and shiny like jewels, about 8 minutes. (You don’t want the cherries falling apart, so err on the side of undercooking them if you’re not sure.) Scrape the cherries onto a plate, spread out in a single layer, and let cool to room temperature. Once the cherry mixture is completely cool, transfer it to the bottom of the prepared pan and smooth into an even layer. Place the pan in the refrigerator to firm the cherries while you make the cake batter.
Step 4Heat the oven to 350 degrees. In a medium bowl, whisk together the remaining ½ teaspoon salt, the flour and baking powder.
Step 5Using your fingers, break apart the almond paste into small chunks and place them in the bowl of a stand mixer or large bowl. Add the butter and mix on low speed until the two are evenly combined, then increase the speed to medium and beat until pale and lightened in texture, about 3 minutes. The firmness of the cold butter helps break apart the almond paste so it stays smooth in the batter, and cutting it into small cubes helps it warm to a smooth, spreadable texture afterward to incorporate into the almond paste easier.
Step 6Add the eggs one at a time, beating well after each addition until smooth before adding the next. Add the milk, lemon juice, vanilla and almond extract (if using), and beat until smooth. Add the dry ingredients and mix on low until just combined. Using a rubber spatula, scrape the bottom and side of the bowl to make sure the batter is well mixed.
Step 7Remove the prepared pan with the cherries from the refrigerator. Dollop the batter evenly over the cherries so it doesn’t disturb them in the bottom of the pan, then gently smooth the top of the batter. Bake until the cake is lightly browned on top and a toothpick inserted in the center comes out clean, 35 to 40 minutes.
Step 8Transfer the cake pan to a wire rack and let cool for 10 minutes. Invert the cake onto a wire rack, remove the pan, then carefully peel back and discard the parchment paper round, replacing any cherries that may try to come off with the paper. Let the cake cool to room temperature before serving. (You technically can cut this cake into smaller wedges than will serve 8, but the cherries will start to fall apart and look rough on top, so stick with 8 even wedges and you’ll be much happier.)