In a large bowl, whisk together the all-purpose flour, salt, baking powder, and granulated sugar.
Add in the butter, and use your hands or a pastry cutter to work it into the dry ingredients until it becomes a coarse meal.
Using a rubber spatula, stir in the sour cream. The dough will be shaggy at this point.
Turn the dough out onto a well-floured work surface and bring it together with a few quick kneads.
Pat the dough into a 10-inch log, roll it out into a 10 x 12 rectangle, and fold it in three.
Wrap the dough in plastic wrap, chill for one hour, and prepare your filling.
In a medium saucepan, combine cranberries, light brown sugar, orange zest, and fresh orange juice and heat until the sugar melts.
Sprinkle in the flour, stir well, and cook until the sauce thickens.
Let the filling cool completely, then preheat your oven to 425°F.
On a lightly floured surface, roll the dough out again, about 16 inches square, and cut out 16 circles.
Brush the edges of eight circles with beaten egg, add a tablespoon of filling, and cover with the remaining circles.
Seal the edges with a fork, brush with egg wash, sprinkle with sparkling sugar, and place on a baking sheet.
Bake for 18 to 20 minutes until golden brown, then cool before serving.
