Combine all dough ingredients in the bowl of a standing mixer (starting with only half a cup of water). Mix for about 10 minutes - dough should be very soft and very sticky. Cover and let rise for about 40 minutes until doubled in volume.

In a medium bowl, combine all filling ingredients. Mix well. If needed, add more oil to dilute the filling into a more easily spreadable paste.

Gently flour your working area to prevent dough from sticking.

When dough has risen, cut it into 2 equal parts. Roll each half into a ball and press to flatten slightly into a round about an inch thick.

Spread cocoa filling on top of both rounds, dividing it equally between the two. Spread filling nicely on each circle, leaving a blank margin of half a centimeter around the diameter.

Taking the dough carefully by its edges, begin to pull the edges towards the centre, turning your round into a ball filled with cocoa mixture. Pinch and pat to close. Make sure there are no leaks and turn seam-side down on a slightly floured surface. Repeat with second half of dough.

Let stuffed dough rest for 30 minutes.

Once dough has rested a second time, with a rolling pin begin to gently roll out each chocolate-filled round, making it as thin as possible. If some liquid comes out, don't worry - just roll it out as thin as it gets without sticking to your surface.

Cover a large baking sheet with parchment paper.

Using a pizza roller, cut the circle into quarters. Then cut each quarter to five or six long, thin triangles. Shape rugelach by rolling the outer edge inward. Arrange rugelach, pointed side down, on baking sheet with a couple of inches in between, leaving room to expand.

Leave rugelach on baking sheet to rise for about 30 mins.

Preheat oven to 400F/200C.

Prepare syrup. Combine all syrup ingredients in a small saucepan over low heat, and cook until the syrup thickens but doesn't come to a boil.

If the syrup is ready before the rugelach are baked, reheat it for a few minutes. Syrup should be spread on rugelach immediately once they are taken out of the oven.

Once ready to bake, bush rugelach lightly with egg, bake at 400F/200C for 20 minutes. Remove immediately, and spread with syrup.

Let cool for just a couple of minutes, and serve. Rugelach will keep best if frozen and reheated briefly in the oven right before serving.