This is a lunchtime favourite for our little girls. I add the extra egg white to the crepe batter, and often use plain Balkan yogurt instead of the sour cream. When I don't have fresh lemons, or if I am lazy, I add 1/4 teaspoon of Boyajian lemon oil instead of the zest.
I haven't made these but they sound like the blintz that 'my' baba made when I was a little girl. Can't wait to try them!!!