Prepare crostata dough: Sift 2 1/2 cups flour. Place flour, butter (minus 1 tablespoon), sugar, salt, and lemon zest in food processor. Pulse until mixture is moistened and crumbly. Add egg yolks and pulse until mixture just begins to form a ball of dough. (Crust can be mixed by hand if you do not have a food processor).
Stir the lemon juice into the preserve and spread the preserves on top of dough, leaving a 2-inch border. Fold the dough border over the filling to form an 8-inch round, pleating loosely and pinching to seal any cracks in the dough. Bake the crostata until the crust is golden, 35 to 40 minutes. Allow to cool.
In saucepan over low heat, warm cherry (or strawberry) jam with remaining 1 tbsp butter. Spread warm jam in a thin layer over the crust, leaving about 1 1/2 to 2 inches around the edges for a border. Spread fresh cherries over the jam.