By late June, the blackberries on the farm have arrived at their peak. The berries are half the size of commercially grown berries and are purple-black and juicy, with tiny seeds and crisp skin, which makes them stand up well in desserts such as cobblers. This biscuit-dough version of cobbler allows you to use more berries, and the dough soaks up more berry juice than other pastry does. The recipe calls for a cast-iron skillet, but this cobbler can also be made in any ovenproof dish. Serve with vanilla ice cream or whipped cream.