The syrup:In a saucepan over medium heat, add syrup ingredients, stir a little then let it boil.When it boils, reduce the heat and simmer for 10-15 minutes.
Turn heat off and let it cool down to room temperature, it will thicken as it cool down.
The filling:Mix the sugar and the cornstarch in a blender until it has a powerdy consistency. That is "confectioners' sugar"Whip the cream with confectioners' sugar until soft peaks form.
Add the pistachio paste and the mascarpone cheese. Mix very well until incorporated.
Finally, to prepare the qatayef batter:In a bowl, combine the dry ingredients well.Add water and mix until everything is well incorporated, cover and let it rest for 30 minutes. You can do this step in a blender.
The batter should be runny and not thick like pancakes.
In a skillet set over medium heat, pour 2 tablespoons of batter.
Cook until the batter has no visible wet spots you will notice bubbles forming on the surface. Do not flip.
Scoop or pipe about a teaspoon of the filling in the middle of the qatayef.
Pinch the edges together sealing them two-thirds of the way.
Dip the open side into ground pistachios. Enjoy!