Heat milk in the microwave until 100°F (38°C) and no more than 110°F (43°C). Add the yeast with a pinch of the sugar. Wait for 10 minutes to let the yeast activate.

In a stand mixer bowl, add the remaining sugar and lemon zest. Rub together with fingertips until sugar looks like wet sand, to release lemon oils.

Add in flour, salt, and milk powder. Stir by hand to combine. Add the milk and yeast mixture and eggs. Mix with dough hook on medium speed (4 out of 10) until dough releases from sides of bowl, about 2 to 4 minutes.

With the mixer running, add in butter gradually, one small piece at a time, waiting until previous pieces are mostly incorporated before adding more. Stop the mixer and scrape down the dough hook and the bowl in between. Once all butter has been added, continue mixing on speed 6 to 8 out of 10 to build gluten, about 7 to 10 minutes. Once done, the dough should be smooth and elastic. You can use your fingers to stretch out the dough and it should form a thin semi-transparent sheet (see the picture in the blog post above).

Scrape the dough out onto a clean counter or workspace. Knead briefly by hand to bring it together, and form into a tight ball. Place in a lightly greased bowl. Cover the bowl with plastic wrap. Let rise at room temp (or a warm spot in winter) until the size increases about 30%, 1 to 2 hours.

While the dough is resting, prepare the black sesame filling. Add the sesame seeds into a medium-sized pan and heat over medium heat until hot, then turn to low heat. Lightly toast seeds until fragrant, then transfer to a small blender. Blend until finely crushed, but not into a paste that releases oil.

Add the honey and sesame oil. Continue blending until mixture comes together and is smooth, scraping down sides between pulses. Place the sesame paste in a medium-sized bowl. Add the chocolate and vanilla, and set aside.

Add the cream, salt and sugar into a small bowl. Heat in the microwave until hot. Stir to dissolve sugar, then pour the hot cream over chocolate and sesame paste. Let stand for 1 minute, then whisk to combine. Add the softened butter and keep whisking until smooth.

Transfer the bowl into the fridge to chill. Stir the mixture occasionally. The paste should be the texture of peanut butter when ready to use.

Once the dough rises, punch down the dough and knead briefly again. Then place it back into the same bowl. Cover and let proof until the size doubles, 2 hours at a warm spot or in a lukewarm oven, 3 to 4 hours at room temp, or overnight in the fridge, for better flavor (if proofing in the fridge, bring dough back to room temp 1 to 2 hours before proceeding with the next step).

Coat 2 loaf pans with nonstick spray. Preheat the oven to 350°F (or 176°C).

Place the dough on a lightly floured surface, gently press it into a rectangle shaped dough. Roll the dough into a 24x 20” (60 cm x 50 cm) thin rectangular sheet, with the long side facing you. Spread evenly with the filling. Roll up the sheet along the long side into a tight coil, starting with the bottom and rolling up. Gently pinch the closed up edge of the dough to seal the filling in.

With a sharp knife, divide the dough into two even pieces crosswise.

Place the rolled up dough in a tray and cover with plastic wrap. Place the tray in the fridge for 1 to 2 hours until the logs turn firm before continuing.

When the dough is ready, work on one at a time. Place the dough on the working surface. Divide it into two even pieces lengthwise. It’s ok if it gets messy, it will be unnoticeable once baked.

Wrap the two dough pieces around themselves starting in the center, for 3 to 4 times, until the length of dough is twisted and braided. Immediately transfer it to the prepared loaf pan. Sprinkle more sesame seeds onto the top for garnishing. Repeat with the other half of the dough using the same method.

(If baking later) The assembled loaves can be refrigerated at this point, up to overnight, and then brought back to room temp and proof before baking.

Cover the pans and let rise for 1 to 1.5 hours. The dough may not appear to rise significantly, but that’s okay.

Bake at 350°F (or 176°C) for 30 to 40 minutes, rotating halfway through, until deeply golden brown on top and internal temperature registers 185°F (85°C).

Add the sugar and water into a bowl and heat in the microwave until turning hot. Stir to dissolve the sugar. Then add the vanilla extract and sesame oil. Stir to combine.

Once the babka is baked, transfer to a cooling rack. Immediately stab the loaves all over with a knife to detach it from the pan, going all the way to the bottom of the pan. Pour half of the syrup over the tops of each loaf. It looks like a lot, but it’s just the right amount.

Let cool completely. Then flip the loaf pan to remove the babka.