Preheat the oven to 350 degrees F. Coat a 13x6-inch baking pan with cooking spray and line with parchment paper; set aside.
Put the cookies into a food processor and pulse into a fine crumb. While pulsing, slowly drizzle in the melted butter. Dump the buttered cookie crumbs into the prepped pan and, using a spoon or offset spatula, spread the crumbs into an even layer. Using the bottom of a heavy glass (or your hand and a piece of wax paper), press down hard on the crumbs, making a firm layer. Bake the crust for about 10 minutes, until it smells toasty and just starts to turn a darker shade of golden brown. Remove from the pan from the oven and set aside to cool.
Wipe out the bowl of your food processor (don’t worry about a few crumbs!) and add the cherries, including the liquid in which they are packed. Puree for at least 2 minutes, getting them as smooth as possible. Transfer the puree to a strainer set on top of a bowl and strain, using a spoon or silicone spatula to turn and press the puree, making sure to extract all of the liquid; only dry pulp should remain.
In a large mixing bowl, whisk together the eggs and sugar until smooth. Add the strained cherry juice, flour, lemon juice, vanilla, and salt and whisk until smooth.
Pour the cherry mixture on top of the cookie crust. Place the pan in the oven and bake to set the curd, 25 to 30 minutes, until the center is just barely wobbly like jello. Remove the pan from the oven and cool on the counter for 1 hour, before transferring to the refrigerator for at least 3 hours or up to overnight.
Carefully lift the parchment paper out of the pan and place on a cutting board. Cut the bars into squares, wiping your knife in between each cut. Top with powdered sugar before serving.