Preheat oven to 425 degrees. In large bowl, whisk together dry ingredients. Gently cut in butter then add yogurt. Mix with hands without overworking dough. Dough should be slightly sticky. Pour onto lightly floured counter and roll to 1-inch thickness. Cut out 2-inch rounds and place on unlined non-stick baking tray. Refrigerate for at least 30 minutes. Brush tops with heavy cream and bake 10 to 12 minutes.