Put the water and the yeast with 2 tbsp of flour in the mixer and cover on top with the rest (we let it rise). 

In a small pot heat the honey, 100 gr butter, the zest, the mahlab, the vanillins and the mastic, until the butter melts, don't brown, just heat.

Next, remove from heat, add the eggs and all of that into the mixer bowl. Mix at low speed until the mixture doesn't stick to the sides of the bowl.  

If it keeps sticking after 20 minutes add a tbsp of flour. Finally add the rest of the butter (50 gr) and beat for a few more minutes in the mixer. 

Cover with a plastic wrap and let it rest for about 1,5 to 2 hours at room temperature until they double. 

When they rise, shape your tsourekia, place them on baking paper and let them rise for an additional 30 to 60 minutes. 

Brush with a bit of egg white and bake at 180 degrees for 20-30 minutes.