Place the currants in a medium-size bowl and pour boiling water over, just to cover. Allow to stand for 10 minutes. Drain the currants, pat dry with paper towels and set aside. Mix the flour, sugar, baking powder and salt in a bowl. Using a pastry cutter or a food processor, cut in the butter until the mixture looks like cornmeal. In a separate bowl, beat the egg slightly with the cream and milk. Pour the egg mixture slowly into the flour mixture, mixing just until the dough holds together in a ball. Fold in the currants. On a floured surface, lightly pat the dough into 2 circles, each about 7 inches in diameter. Cut each circle into 6 even pieces. Place the scones on a buttered baking sheet 2 inches apart. Sprinkle them with optional sugar, if desired. Bake about 15 minutes, or until the scones are puffed, golden and cooked through. Serve them with butter, whipped cream and/or jam.