In a large bowl whisk together flour, cornstarch, sugar and baking powder, make a well in the centre and add the egg and butter combine with a fork until mixture starts to come together.

Move to a lightly floured flat surface and knead until you have a soft smooth dough (if too sticky then add a little extra flour if too dry add a little more butter (a tablespoon at a time).

Wrap the dough in plastic wrap and refrigerate for 30 minutes.

Pre-heat oven to 350F (180C) and line 2 cookie sheets with parchment paper.

Roll half the dough at a time on a floured flat surface until the thinness of a pie crust (a little thicker if you desire) cut out with a small (2 1/4 - 2 1/2 inches / 6 centimeter) cookie cutter.

Place a teaspoon of jam in the middle of the circle and take the two ends and pinch them together, dip fingers in a little water to make sure that the dough sticks and doesn't open while baking. Place cookies on prepared cookie sheets and bake for approximately 12-15 minutes. Let cool completely then dust with a little icing / powdered sugar. Enjoy.