In a large bowl, combine the flour, yeast, salt, and cornstarch. Whisk to combine. Make a well in the center of the bowl, then add the melted butter, egg, avocado oil, milk, and raw honey. Stir with a wooden spoon to combine. When the mixture becomes thick and sticky, start mixing by hand. Pinch to incorporate the ingredients. Begin kneading the dough in the bowl, by hand, until it becomes fairly smooth, and forms a ball. This should take about 3 minutes of kneading. Cover the bowl with plastic wrap, and let the dough rise at room temperature for about 1.5 hours or until it has doubled in volume.

Divide the risen dough into two equal pieces. Sprinkle your work surface generously with flour. Sprinkle the dough lightly with flour. Roll one piece of dough out into a large rectangle, about 14" x 10". The dough should be very thin. Add more flour under the dough as you roll, to prevent sticking.

Warm the Nutella in a micro wave for about 15 seconds so it’s easy to pour, but not hot. Spread 2/3 cup of Nutella onto the rectangle of dough in a thin layer, using a small offset spatula. Leave 1/2" border all around. With the long edge facing you, fold the dough up in half lengthwise, enclosing the chocolate filling. Gently tug the edges and corners to meet, and use fingertips to press down the edges to seal. This helps prevent the Nutella from escaping.

Use a pizza wheel or sharp chef's knife to cut the dough into large triangles. Pick up one triangle, and gently stretch the triangle out even more lengthwise. Place the dough back down on the work surface, and roll the dough - starting from the straight edge top of the triangle, rolling down into a crescent shape.

Place the shaped rugelach in a parchment lined 9-inch round cake pan. Place the rugelach close together, they should definitely be touching. Repeat the same process with the remaining triangles of dough. Then, repeat with the remaining piece of dough. Cover with a clean kitchen towel, and let proof at room temperature for 1 hour.

Meanwhile, preheat the oven to 375°F.

Make the Simple Syrup: In a small sauce pan, combine the granulated sugar and water, and lunch of salt. Whisk to combine. Allow the mixture to come to a boil, and let simmer for 3 minutes, until the mixture thickens slightly, and all of the sugar dissolves. Set aside.

Bake the Rugelach:

Beat 1 egg in a small bowl, and brush the top of each rugelach with beaten egg. Bake for about 30-35 minutes, rotating the pan 180° halfway through to ensure even browning. The rugelach should be deeply golden brown, almost mahogany on top.