Sift together flour, baking powder, and sugar substitute. Cut in the margarine until mixture resembles a coarse meal. Add yogurt and egg; mix together to form a firm dough. If dough is too sticky, add a little more flour. Refrigerate dough overnight.

Preheat oven to 375 degrees F (190 degrees C).

Divide dough into three pieces. On a clean, floured surface, roll out each piece of dough to 1/8 inch thickness. Spread with the sugarless jam, then sprinkle with the nuts and raisins. Roll the dough up tightly like a jelly roll. Brush each roll with beaten egg, and bake for 10 to 15 minutes. Rolls should be golden brown. While they are still hot, cut on a diagonal into 1 inch thick slices, and let cool.