The Dough: Place in a food processor the flour, baking powder, salt and sugar and process for 3 sec.
Add orange zest and butter and process again untilled the butter is assimilated in the flour , then add egg yolks and process until crumbs.
Add 2 tbs of orange juice and process until the dough is smooth and if the dough isn't smooth add a tbs of orange juice again.
Wrap the dough in plastic wrap and put in the fridge for two hours.
Flatten the dough to a midium thickness using flour that the dough won't stick to the work surface.
Cut midium circles in the dough using a glass or a cutter.
Ones you have the circles , apply egg white bitten with a little cold water to the edges adhere well to each other when folding.
Add half of tsp of the filling at the center of each circle.
The poppy seed filling: Bring water to boil and add the sugar.
Add poppy seeds and bring to boil again, then reduce the heat and simmer for 10-15 min until the mixture is thick and reduced.
Remove from heat and add honey and lemon juice.
Stir and put aside to cool.
The folding: Hold the circle filled in your hand.
With four fingers, the first and second finger of both hands fold in creating a triangle.
Press hard the edges of the triangle while strengthening the triangle shape.
Arrange on a baking paper and refrigerate for half an hour.
Preheat the oven to 170c .
Spread the cookies with the beaten egg whites with a brush and bake for 15-20 min or the cookies are nicely golden.
Cool and sprinkle with sugar powder.