Preheat oven to 375°F. In a large bowl, whisk together the dry ingredients. Cut in the butter with a pastry cutter or two knives; or rub together with your fingers. Mixture should look like coarse meal with some pea-sized pieces of butter. Add any extras (herbs, cheese, etc). Make a well in the centre and pour in one cup of cream (or buttermilk, if using). Stir with a spoon until just combined and no dry flour remains. Add more cream, 1 tablespoon at a time, if needed to fully moisten the dough. Drop by large spoonfuls onto ungreased baking sheet. Bake until golden brown and cooked through, about 20 minutes. Serve within half an hour. * For the richest, most tender biscuits, use heavy cream and don't think about the fat content -- let a hearty, tomato-based bean-and-vegetable soup be the virtuous partner in this duo! But if you can't do that with a clear conscious, use a lighter cream (table cream or half'n'half). Buttermilk is an excellent low-fat alternative. The biscuits won't be quite as tender but they'll have great flavour.