While the blueberries are baking, prepare the ingredients for the topping, but do not stir the wet ingredients into the dry ingredients until just before the berries come out of the oven. A standard or deep-dish 9-inch pie pan works well; an 8-inch square baking dish can also be used. Vanilla ice cream or lightly sweetened whipped cream is the perfect accompaniment. To reheat leftovers, put the cobbler in a 350-degree oven for 10 to 15 minutes, until heated through.