I am amazed that the little bit of sour cream in this dough produces a flaky pastry that melts in your mouth. You can freeze this dough to slice and bake when you feel like it.

Makes 36
1/4 c sugar
1 1/2 tsp cinnamon
1 c flour
145g cold butter, cut into pieces
1/3 c sour cream
1 tsp vanilla extract

Mix the sugar and cinnamon together in a small bowl.
Use an electric mixer to mix the flour and butter in a bowl until the butter is in small pieces. Add the sour cream and vanilla and beat until the dough forms into smooth clumps, about 30 seconds. 
Turn out onto a floured surface and shape into a rectangle. Roll to about 46cm long and 40cm wide, with the short side facing you. Sprinkle the cinnamon sugar evenly over the dough, leaving 2.5cm bare on each edge, and leave 1 tbsp in the bowl.
Roll up the bottom edge tightly until you reach halfway up the dough. Then roll the top of the dough down tightly to the bottom roll. Pinch the seams along the length of the roll to seal it and the ends as well. Sprinkle the rest of the sugar over the roll and roll it back and forth to coat evenly.
Cut the roll in half crosswise and wrap each piece in cling film. Refrigerate to at least 3 hours or overnight until firm, or wrap in foil and store in the freezer for up to 2 months.
When ready to bake, preheat oven to 180C and line 2 baking sheets with baking paper. (If you're defrosting the dough from the freezer let it defrost overnight in the fridge). Cut the cold logs into 8mm thick slices and place on your baking sheets about 4mm apart.
Bake until just brown, around 15 minutes. Let cool on the baking sheets for 10 minutes then transfer to a wire rack to cool completely.