bread and butter pickle recipe

read and Butter Pickles Ingredients: 4 cups thinly sliced cucumbers (about 1 1/2 pounds) 1 cup thinly sliced onions 1/4 cup kosher salt 2 cups ice cubes 1 1/2 cups granulated sugar 1 cup white vinegar 1/2 cup apple cider vinegar 1/4 cup light brown sugar, packed 1 tablespoon mustard seeds