My children love this cookie. I make it every week. Try it yourself. 

#cookie
the dimensions i use
glass of water: 200 ml
tea cup: 125 ml
125 g butter
half a teaspoon of oil
1 egg yolk
2 teaspoons of powdered sugar (10 g)
2 tablespoons of vinegar (10 g)
1 teaspoon of salt (5 g)
1 teaspoon of baking powder (5 g)
1 teaspoon of mahaleb (5 g)
2.5-3 glasses of flour
For the above
1 egg white
half a glass of sesame (70 g)
1 teaspoon of black cumin (5 g)