clues
make the basic dough:
add the milk to the bowl of a stand mixer fitted with a dough hook. use a fork or your fingers to lightly mix the yeast into the milk. then, in this order, add the flours, eggs, sugar, salt, and finally the butter in small pinches.
mix on the lowest speed, stopping the mixer to scrape down the sides and bottom of the bowl as needed, and to pull the dough off the hook as it accumulates there and break it apart so it mixes evenly, until the dough is well combined, about 2 minutes (it will not be smooth).
if the dough is very dry, add more milk, 1 tablespoon at a time; if the dough looks wet, add more all-purpose flour, 1 tablespoon at a time, until the dough comes together. increase the mixer speed to medium, and mix until the dough is smooth and has good elasticity, 4 minutes.
stretch and fold the dough:
lightly dust your work surface with flour and turn the dough out on top; lightly dust the top of the dough and the interior of a large bowl with flour. grab the top portion of the dough and stretch it away from you, tearing up the dough. then fold it on top of the middle of the dough, give the dough a quarter turn and repeat the stretch, tear, and fold. continue to do this until you can stretch a small piece of dough very thin without it tearing, about 5 minutes. then use your hands to push and pull the dough against the word surface and in a circular motion to create a nice round of dough. set the ball in the floured bowl, cover the bowl with plastic wrap, and set it aside at room temperature for 30 minutes.
chill the dough:
set the dough on a piece of plastic wrap and press it into a 1-inch-thick rectangle. wrap the dough in plastic wrap and refrigerate it for 24 hours.
[at this point you've completed the "basic babka dough." if you'd like to skip to the sesame seed toasting and filling steps, that is ok! but if you're in this for the long haul and want to make the "advanced babka dough," go onto the next step.]
prepare the butter:
set the 200g butter on a large piece of parchment paper. use a rolling pin (or your fist) to smack and whack it into a 7-by-8-inch rectangle that is between 1/8 inch and 1/4 inch thick. use a bench knife to square off the corners and then pound as needed to fit the measurements. set the butter aside.
add the butter and make the first fold:
place the dough on a lightly floured work surface, lightly dust the top, de-gas the dough by pressing down on it, and then roll the dough into a 7-by-16-inch rectangle with a short side facing you. place the butter on the bottom half of the dough, leaving a 1/4-inch border at the bottom. fold the top of the dough over the butter to meet the bottom edge, pull the corners so they align perfectly, and use a pastry brush to brush away any excess flour from the surface.
fold and chill the dough:
rotate the dough so the seam side (which was facing the bottom) is now facing to the right. lightly flour the top and underside of the dough, and roll it into a 9-by-16-inch rectangle. use a bench knife or a chef's knife to square off the edges (save the scraps to add to the dough). then use your finger to mark the dough into equal thirds. use a pastry brush to remove any excess flour from the dough. fold the bottom up to the top mark and the top down and over to the bottom edge to create a simple fold. try to keep the edges and corners as perfectly aligned as possible. lightly dust the dough and the work surface again, and roll the dough just enough to flatten it slightly. at this point, the dough will probably bounce back when you roll it because you have been working the gluten a lot. now is a good time to wrap it in plastic and let it rest in the refrigerator for 30 minutes, then repeat the simple fold two more times, refrigerating the dough between each time. wrap the dough in plastic wrap and refrigerate it for at least 5 hours or overnight.
toast the sesame seeds:
place the sesame seeds in a small skillet over medium-high heat and toast them, shaking the pan often, until they are golden brown, 2 to 3 minutes. transfer the seeds to a small plate and set aside.
roll the cold babka dough:
unwrap the cold babka dough and set it on a lightly floured work surface. roll the dough into a 12-by-28-inch rectangle (it should be just a little shy or 1/4 inch thick) with a long side facing you. pull and shape the corners into a rectangle.
fill and roll the dough:
spread the labne over the dough in a thin, even layer. sprinkle it with the jalapeno, olive oil, feta, toasted sesame seeds, pine nuts, oregano, and za'atar. divide the dough in half horizontally so you now have two 6-by-28-inch pieces. working from the long bottom edge of one of the pieces, roll the dough up into a tight cylinder, pushing back on the cylinder with each roll to make it even tighter. lift the cylinder, holding one end in each hand, and gently stretch and pull to tighten it even more (it will stretch to about 35 inches long). repeat with the second piece of dough.
divide the dough into strips and make the mini babkas:
use a bread knife to slice each cylinder in half lengthwise so you have 4 long pieces, and then slice those pieces crosswise into 7 equal sections (about 5 inches each) to make a total of 28 strips. cross 2 equal-size pieces to create an X, keeping the exposed filling facing up. twist the ends together like threads on a screw so you have at least 1 twist on each side of the X (3 twists total). repeat with the remaining pieces. set twists in a lightly greased mini loaf pan.
let the mini babkas proof:
cover the pans with plastic wrap and set aside in a warm, draft-free spot until the babkas have doubled in volume and are very soft and jiggly to the touch, 2 to 3 hours depending on how warm your room is.
preheat the oven to 350ºf.
bake:
make the egg wash by whisking the egg, water, and salt together in a small bowl. brush egg wash over each mini babka, and bake until they are dark brown and baked through, about 20 minutes; check after 15 minutes, and if they are getting too dark, tent them loosely with a piece of parchment paper. remove from the oven and, while they are still warm, brush with more olive oil and sprinkle with a little za'atar. serve warm or at room temperature.
