First day - first proofing of the dough

• Start with mixing half of the sugar with the lukewarm milk then sprinkle yeast on top. Make sure that the kitchen is nice and warm, and in 10 minutes, the yeast should start to foam.
• Place the yeast mixture into your stand mixer with the kneading hook on, then mix it together with the room-temperature eggs.
• Pour in dry ingredients: bread flour, rest of the sugar, and salt, and start kneading it until the dough comes together. This will take about a minute or two.
• Then, slowly add the room-temperature (soft) butter chunks by piece to the dough. Once all the butter is in, knead the dough for another 10 minutes on medium-high speed until it becomes elastic and shiny and not too sticky.
• Move the dough into a bowl, cover it with plastic wrap and let it rest and rise in the fridge overnight for 12 hours.
• Alternatively, rise the dough for 1-2 hours at room temperature in a warm but not hot (avoid direct heat) spot in your kitchen. However, I do not recommend skipping the overnight rise, as the dough is much easier to handle while cold.

Second day

Make the cinnamon sugar filling

• Cream the room temperature butter, sugar and cinnamon for a few minutes until slightly increases in volume, then add a pinch of salt. Set it aside.

Second proofing

• Try to work quickly, and have everything you need - rolling pin, measuring tape, cinnamon sugar filling, a loaf pan with parchment paper prepared upfront. If the dough is warming up, pop it in and out of the freezer for a few minutes to chill between the steps, making sure the dough is always cold enough to work with and does not tear or stick. Refrain from using an excessive amount of flour, as that would make the cinnamon babka hard.
• So, after the dough has risen overnight, take it out from the fridge and punch the air out of it. Then, on a lightly floured surface or on a silicone baking mat, roll it into a rectangle of 30x42 cm / 12x16 inches.
• Spread the cinnamon sugar filling on top and roll the dough up evenly and tightly from the shorter end, and then press to seal the end onto the roll. So you will end up with a 30cm / 12 inches long roll.
• If the dough is still nice and cold, continue with shaping. Otherwise, chill it first for about 5 minutes in the freezer. Cut the babka into half lengthwise, then place the logs over each other with the filling facing up and twist the logs with your hands on both sides.
• Gently squeeze together the ends and then carefully lift the cinnamon babka into your prepared loaf pan.
• Cover the loaf pan with a kitchen towel and proof the cinnamon babka now the second time now at room-temperature. Proofing might take 1-2 hours, depending on your kitchen temperature. Wait until the dough doubles in size.

Baking

• Pre-heat your oven to 180C / 355F (no fan) towards the end of the proofing time. Then, once the babka is doubled in size, bake it at 180C / 355F for about 40 minutes. Bake until a skewer inserted comes out clean and the babka is golden brown. If it was browning too much, place aluminum foil on top towards the end of the baking time.

Syrupy glaze - optional

• For extra shine, towards the end of the baking time, make the syrup: boil water, sugar, and freshly squeezed lemon juice together until the mixture reaches a syrup consistency. Apply the syrup with a pastry brush on top of the hot babka. Let the babka slightly cool before removing it from the tin to a cooling rack - with the help of the parchment paper.
• Serve the cinnamon babka fresh. Any leftovers can be stored in an air-tight container at room temperature for 2-3 days.