Place blueberries in a bowl with enough hot water to cover. Soak for about 5 minutes. Preheat oven to 450 F. Drain blueberries. Mix together flour, baking powder, 1 Tbsp sugar and salt in a bowl. Cut in butter, using a pastry blender or two knives. Stir in blueberries. In a separate bowl, beat eggs. Reserve 2 Tbsp and add remaining eggs to dry ingredients. Pour in cream. Combine with a few swift strokes. Place on a slightly floured board and pat or roll to a thickness of 3/4 inch. Cut with a knife into diamond shapes or into 2-inch rounds. Brush with reserved egg and sprinkle with sugar. Bake for 15 minutes.