Preheat oven to 450°F. Mix first four ingredients in a bowl. With a pastry knife or 2 knives, cut in shortening until it resembles corn meal. Add cream. Separate one egg and reserve 1 tablespoon of the white. Beat the rest of the egg with the other egg and add to flour mixture.
On a lightly floured surface, roll dough to ½ ” thick. Cut into 3 ” squares then divide these into two triangles. Arrange on a greased cookie sheet. Brush with egg white, slightly beaten. Sprinkle with 2 tablespoons sugar. Bake 10 to 15 minutes. Serve hot with clotted cream and jam.