Place the flour, margarine, baking powder, and wine into the bowl of your mixer. Using a cookie paddle or dough hook, mix well until a smooth but slightly sticky dough has formed. Wrap dough in parchment paper and place in the refrigerator for about 30 minutes to chill.

Line two baking sheets with parchment paper and sprinkle with flour. Set aside.

Divide dough into six even parts. Roll each part out into a 10×15-inch (25×38-centimeter) rectangle. Divide the filling evenly over each rectangle and spread over the dough, leaving a 1/2-inch (one and 1/4-centimeter) border of dough at the edges. If using date filling, sprinkle the filling lightly with cinnamon. Roll each rectangle up tightly in the length, creating six long logs. Using a sharp knife, score the dough across the tops of each of the logs at 3/4-inch (two-centimeter) intervals.

Preheat oven to 375 degrees Fahrenheit (190 degrees Celsius). Place three logs, evenly spaced, on each of the prepared baking sheets and bake on the center rack of the oven for 40–45 minutes, until lightly golden. Be sure not to overbake, as the logs can dry out.

Remove from oven and allow to cool for at least 30 minutes. Sprinkle the logs very generously with confectioners’ sugar and lightly with vanilla sugar. Using a serrated knife, slice logs gently at each score mark.