Step 1

In a small bowl mix together sour cream and vanilla. Set aside.

Step 2

Using a pastry blender or (several pulses with a food processor) cut together flour and butter so butter is reduced to small pea-sized bits. Stir in sour cream mixture. Blend well to form a dough. Divide into two disks. Flatten disks slightly, cover and chill at least 2 hours or overnight.

Step 3

Preheat oven to 450°F. In a small bowl whisk together egg and sugar. Set aside. On a floured work surface, roll out each dough disk into a 12 by 6 inch rectangle. Spread filling down center in a thin strip leaving two inches clear on each side and an inch and a half at both ends. Fold sides over center then fold ends up, press lightly to seal. Brush with egg wash.

Step 4

Bake on a parchment lined cookie sheet for 10 to 15 minutes or until golden brown. Drizzle icing over warm kringle. Cool on wire rack. Store in a covered container. Best within a day.