Preheat oven to 400°F and line a sheet pan with parchment paper.
In the bowl of a food processor, pulse together the flour, baking powder, sugar, and salt. Add the butter cubes and pulse until the mixture is coarse with pea-sized clumps.
Add the butter and cream and pulse until the dough comes together away from the sides of the bowl. If the dough is still to dry, add some cream or milk about a tablespoon at a time until it is sufficiently moistened. Turn out the dough onto a floured surface and shape into a disk about 1 inch in height. Use a cookie cutter to cut to into circles.
Place scones on the sheet pan and brush with egg wash. Bake for 15-20 minutes or until top start to turn golden brown.