Place flour in a mixing bowl and with 2 knives cut in the butter or margarine till the mixture resembles small peas. Stir in the sour cream and vanilla till the dough holds together. On your floured work surface knead the dough about 10 times. Divide the dough into 3 pieces and wrap in plastic wrap. Refrigerate for 20 minutes.
Roll one piece of the dough at a time into 10 inch circle. This is like making pizza. Spread the dough with 2 tbsp of jam and sprinkle with one third of the chopped white chocolate. Using a pizza cutter cut the dough into 12 wedges. Starting at curved edge, roll up each wedge and place point-side down, on an ungreased baking sheet. Repeat with the remaining dough.
In a small bowl stir together the sugar and cinnamon if desired and sprinkle over each cookie. If you are trying to cut back on sugar, you can omit this step.
Bake at 375 degrees for 20 to 25 min or until light golden brown.
This recipe yields about 3 dozen cookies.
Please keep in mind that nutritional information is a rough estimate and can vary greatly based on products used.