Step 1

To make the dough: Place flour, sugar, and yeast in the bowl of a standing mixer fitted with the dough hook and mix on low speed until combined. Add eggs, water, and lemon zest, and mix until dough comes together, 2-3 minutes. While mixer is running, add butter, a few cubes at a time, and mix until incorporated, about 5 minutes. Add salt and continue mixing for another 5 minutes on low speed, until the dough is completely smooth and elastic and pulls away from the sides of the bowl. During mixing, scrape down the sides of the bowl using a spatula as needed.

Step 2

Place dough in a large bowl brushed with oil (the fat will keep the dough from drying out), cover with plastic wrap, and leave in the fridge for at least half a day or overnight. Alternately, place on counter at room temperature for 1½-2 hours or until doubled in size.

Step 3

Grease two 2¼-lb/1kg loaf pans (9×4 inch/23×10 cm) with oil and line the bottom of each pan with parchment paper for easy release later on. Set aside.

Step 4

Rolling and shaping (photos here): Divide dough in half. Roll out dough on a lightly floured surface and shape into a rectangle measuring 16×14 inches (40×35 cm). Position dough so that the long side is closest to you. Using an offset spatula, spread half of the Nutella spread over the rectangle, leaving a ½-inch/1cm border all around. Sprinkle half of the chocolate chips or nuts on top.

Step 5

Use both hands to roll up the rectangle like a roulade, starting from the long side closest to you and ending at the other side. Press to seal the dampened end onto the roulade, then use both hands to even out the roll into a perfect thick cigar. Rest the cigar on its seam.

Step 6

Using a serrated knife, gently cut the roll in half lengthwise, starting at the top and finishing at the seam. You should have two long, even halves with the layers of dough and filling visible along the length of both. With the cut sides facing up, gently press together one end of each half, then lift the right half over the left half. Repeat the process again, this time lifting the left half over the right to create a simple two-pronged plait. Gently squeeze together the other ends so that you are left with two intertwined halves showing the filling on top.

Step 7

Carefully lift cake into a loaf pan. Don’t worry if there are gaps in the pan since the cake will rise and look fine, even if you feel like it’s messy at this point. Cover the pan loosely with plastic wrap and leave to rise on the counter for 1 to 1½ hours (in warm weather it can take 45 minutes). Repeat using the remaining dough and Nutella to create the second cake.

Step 8

Preheat oven to 350F/180C, making sure to allow plenty of time for it to heat fully before the cakes have finished rising. Remove plastic wrap and place cakes on middle rack of oven. Reduce heat to 340F/170C and bake for 35 minutes.

Step 9

While the cakes are in the oven, make the syrup. In a small saucepan over medium heat, bring water and sugar to a boil. As soon as the sugar dissolves, remove from heat and set aside to cool. Once the cakes are out of the oven, brush the syrup over them. Use all of the syrup, even if it looks a lot. Let cakes cool until they are warm, then remove from pans and let cool completely before serving. Serve warm or at room temperature.

Step 10

Babka will stay fresh for 24 hours in an airtight container at room temperature. Do not place in the fridge. It also freezes well for up to 2 months. To thaw, leave on counter or overnight in the fridge.