Center a rack in the oven and preheat the oven to 400°F.
Line a baking sheet with parchment
In a small bowl, stir the egg, cream and vanilla (if using) together.
Whisk the flour, sugar, baking powder and salt together in a large bowl.
Drop in the butter and, using your fingers, toss to coat the pieces of butter with flour. Quickly, working with your fingertips or a pastry blender, cut and rub the butter into the dry ingredients until the mixture is pebbly.
Pour the egg, cream and currants over the dry ingredients and stir with a fork just until the dough, which will be wet and sticky, come together. Don't overdo it. Still in the bowl, gently knead the dough by hand, or turn it with a rubber spatula 8 to 10 times.
You can also use a food processor. Place dry ingredients in bowl, pulse 1-2 twice to mix. Add butter and pulse 5-6 times until mixture looks like crumbs. Add egg/cream and pulse to dough just begins to clump. Do not overmix! Take mixture out of processor bowl, fold in peaches and shape dough into circles, proceed as below.
Lightly dust a work surface with flour and turn out the dough. Divide it in half. Working with one piece at a time, pat the dough into a rough circle that's about 5 inches in diameter, cut it into 6 wedges and place it on the baking sheet.
Brush scones with heavy cream and sprinkle with sugar
Bake the scones for 20 to 22 minutes (start checking at 15 min) or until their tops are golden and firm. Transfer them to a rack and cool for 10 minutes before serving, or wait for them to cool to room temperature.
The scones can be frozen on the baking sheet as the cut wedges, then wrapped airtight. Don't defrost before baking- just add about 2 minutes to the baking time.
Serve with jam and clotted cream or butter