Sift flour, baking powder, sugar, and salt together into a large bowl. Cut in butter until small pea sized. Beat eggs in a separate bowl. Reserve 2 Tbsp of egg. Beat cream into the remaining egg. Make a well in the dry ingredients. Pour in the liquid and combine with a few rapid strokes. Handle the dough as little as possible. Place it on a lightly floured board. Flour hands, and pat dough to 3/4 inch thick. Cut into diamonds, squares, or whatever shapes you want. Brush with reserved egg and sprinkle with salt or sugar. Bake 15 minutes at 450.
Optional additions (add to dry mixture after cutting in the butter)