Using an electric mixer, blend sugar and butter until very creamy. Add egg and blend until thoroughly combined.
Combine flours, baking powder and cinnamon in a separate bowl.
Add dry ingredients to batter, a little at a time, until thoroughly combined.
This makes a dense shortbread dough.
Place in refrigerator for at least a few hours or overnight.
Preheat oven to 350 F.
On a lightly floured board, roll out dough.
Roll out dough as thin as possible. Using a round cutter, cut out circles (you can use whatever size you prefer). Place about a teaspoon of the preserves in the center.
Fold in the sides to make a triangle.
Place on a cookie sheet lined with waxed paper or parchment paper.
Bake for 15-20 minutes, until golden brown.