Divide the pastry into 3 (5-inch) squares about 5/8 inch thick. Wrap in plastic and refrigerate until cold and firm, at least 4 hours.
To make the filling, process all of the filling ingredients in a food processor bowl until mixture is smooth and blended.
Remove 1 pastry square from the refrigerator. Set a side for 10 minutes before rolling it. On a floured work surface, roll the pastry into a rectangle until less than 1/8-inch thick. With a ruler and a pastry wheel, trim the ragged edges and then cut the pastry into 3-inch squares. Lay the pastry squares across the top of an un-greased 12-cup miniature muffin pan, each cup measuring 1 1/2 inches across and 3/4 inch deep, centering each square over one cup. Spoon 1 heaping teaspoon of filling on each square, then bring opposite corners to the center and press lightly to seal. This process will also ease the pastry into each cup. Refrigerate for at least 30 minutes. Roll and shape the remaining pastry squares in the same fashion.
Adjust rack to lower third of oven and preheat to 375 degrees F.
Bake 2 or 3 pans at a time for about 20 to 25 minutes or until pastries are light brown. Remove pan from oven to a wire rack for about 10 minutes. Remove pastries from pan to a wire rack to cool completely. Sift powdered sugar and cinnamon together and sprinkle pastries before serving at room temperature. If not serving the same day, stack the pastries in airtight plastic containers and freeze for up to 2 weeks. To serve, reheat to freshen in a 325 degree preheated oven for about 7 to 12 minutes or until warm, cool slightly, and decorate with powdered sugar and cinnamon.
Put the flour and salt in a 3-quart bowl, and stir to blend. Scatter the butter slices over the flour, and cut in with a pastry blender until the mixture consists of particles that vary in size from small peas to bread crumbs. Stir in the sour cream with a fork. The pastry will appear dry because the sour cream is thick and does not disperse easily. With your hands, manipulate dough into a ball. Divide dough as recipe directs. Wrap in plastic and refrigerate until cold and firm, at least 4 hours and up to 3 days. The dough can be frozen for up to 1 month.