Make the dough

• Place flour, cinnamon, dry yeast and sugar in the bowl of a stand mixer and whisk to combine.
• Add warm milk, melted butter and vanilla and knead with the hook attachment until just combined. Add salt and keep kneading on medium until the dough is smooth and elastic.(About 10 minutes).
• Shape into a ball, place into a lightly greased bowl, cover it with plastic wrap or a damp towel and let it sit in a warm place until the dough is doubled in size, about 2 hours.
• While the dough is rising, make the chocolate filling. Gently melt chocolate and butter over a Bain marie (double boil). Add agave, cinnamon and salt and stir to combine. Set aside to cool down to room temperature.
• Once the dough has risen, gently deflate and roll out onto a lightly floured surface. Roll the dough into a 40×60 cm (16"x23") rectangle. If the dough fights you, let it rise for a few minutes until it is relaxed enough to roll into shape.
• Gently spread a thin layer of the chocolate filling evenly on the surface of the dough, leaving 1 cm on the upper side.
• Starting from one long edge, gently roll dough into a log and seal the ends. Coil the log into three equal pieces (into an S-shape) and place into a lightly greased 20cm-loaf pan. (gently press to fit the pan).
• Let rise the prepared babka for 1,5-2,5 h, until the dough has almost reached the border.
• Preheat oven to 175C degrees. Bake for 15 minutes, then lower heat to 150C degrees and bake for another 45 minutes or until evenly golden brown.