"This onion-studded, poppy-seed-tangled bialy babka is the sort of wildly comforting loaf that will have you preheating the oven and texting friends to come over IMMEDIATELY!
A bialy is a chewy, palm-sized roll with an indentation filled with cooked onions and poppy seeds. A bialy babka ribbons those flavors through a rich, stretchy enriched dough and bakes them into a loaf — all the oniony goodness, but cut into thick, buttery slices.
In the bowl of a stand mixer (or a large bowl if kneading by hand), whisk together the melted butter, milk, instant yeast, sugar, salt, whole egg, and egg yolk until combined.
Add the flour. Using the dough hook, mix on low to bring it together, then knead on low speed 5–7 minutes, until the dough is soft and stretchy.
Transfer dough to a lightly oiled bowl, cover tightly with plastic wrap, and set in a warm spot until about doubled, about 1½–2 hours.
Tip: If your kitchen is cold, preheat the oven to 200°F (95°C) for a few minutes, turn it off, and place the covered bowl inside to speed the rise.
(Optional) For a longer fermentation or to bake the next day, chill the dough in the fridge. If chilled, remove ~1½ hours before using so it warms up enough to roll.
Melt 2 tablespoons butter in a large sauté pan over medium heat. Add the diced onions, toss to coat, and cover.
Reduce heat to medium–low and let the onions slowly sweat for 12–15 minutes, stirring once or twice — you can walk away.
Uncover, raise heat slightly, stir in 3/4 teaspoon salt, and continue to cook, stirring every ~5 minutes for 20–30 minutes, until the onions are very tender and golden but not fully deeply caramelized.
Raise heat to medium–high for another ~5 minutes so edges get a touch darker. Spread onions on a plate to cool quickly.
Note: You want sweet, concentrated onion flavor, not the hours-long jammy caramelization used for French onion soup.
On a generously floured counter, roll the dough into a rectangle roughly 12 inches wide (closest to you) and as long as you can comfortably roll (about 10–14 inches), rolling fairly thin.
Spoon and spread the cooled onions evenly over the dough, then sprinkle with 2 teaspoons poppy seeds.
Roll the dough away from you into a tight log/coil. Transfer the log to a parchment-lined tray and chill in the freezer 5–10 minutes — this firms it and makes cleaner slicing.
Meanwhile, prepare a standard loaf pan: butter or spray it, and line the bottom + two sides with a parchment sling for easy removal.
Remove the chilled log and, with a serrated knife, gently slice it lengthwise into two long strips. Place them cut-side up, parallel.
Lift one strip over the other and twist/pleat them together, keeping the cut (oniony) sides facing up so the interior layers show.
Transfer the twist into the prepared loaf pan. Cover with plastic wrap and let proof ~45 minutes at room temperature — it may not swell hugely; this lets the gluten relax.
Preheat oven to 350°F (175°C).
Sprinkle a few extra poppy seeds over the top. Bake 40–45 minutes, until a skewer comes out without sticky dough or an instant-read thermometer reads ~185°F (85°C) in the center.
If the top browns too quickly, tent with foil for the last few minutes.
Let the babka cool in the pan as long as you can stand it, then lift out using the parchment sling and slice with a serrated knife.
Serve warm, spread with butter or cream cheese; it’s also excellent with lox.
Cheesy French-Onion version: Sprinkle 1–2 cups grated Comté, Gruyère or baby Swiss over the onions before rolling.
Timing: Most of the time is passive rising and baking — active work is modest (rolling, cooking onions).
Make-ahead: Onions can be made a day ahead and refrigerated. Dough can be retarded in the fridge overnight; bring back to near room temperature before shaping.
Storage: Wrapped in foil or an airtight bag, the loaf keeps at room temp a few days. Re-toast or warm gently to refresh.
Freezing: Slice and freeze, then toast straight from frozen.
Temperature tip: Use the internal temp (~185°F / 85°C) if you’re unsure the center is done.
