Crust: Preheat oven to 375°F. Butter an 8-inch square cake pan.

Beat butter with sugar on medium-high speed until pale and fluffy, about 3 minutes, scraping down bowl as needed. Reduce speed to medium-low, add flour and salt, and beat until dough forms clumps but does not completely hold together. Press 2 1/2 cups flour mixture into bottom and 1 inch up sides of prepared pan.

Filling: In a medium bowl, stir together cherries, sugar, flour, lemon juice, and salt. Pour into crust. Crumble remaining flour mixture (about 1/2 cup) evenly over top, squeezing to create clumps.

Bake until bubbling in center and crust is golden, about 1 hour, 10 minutes (if browning too quickly, tent top with foil). Transfer to a wire rack and let cool at least 20 minutes before slicing into squares.