Babka dough

1. In the bowl of a stand mixer or a large mixing bowl, whisk together the flour, yeast, sugar, cinnamon and salt. 
2. Add the lukewarm milk, olive oil and lemon zest, and mix to form a rough dough. The milk should be warm but not too hot, slightly under 100 degrees F (37°C) not to kill the yeast. If using a stand mixer, mix with the hook accessory until the dough is smooth, elastic and not sticky. If not using a stand mixer, start mixing the dough with a spatula until combined. Then transfer the dough to a lightly floured surface and kneed for about 10 minutes until smooth.
3. Form a loose ball with the dough and place it into a lightly greased mixing bowl. Cover with a clean damp towel and leave it in a warm place for 60-90 minutes, until the dough doubles in size.

Caramel hazelnut lemon filling

1. Meanwhile prepare the filling. Soak the pitted dates in warm water for 20 minutes to soften. It’s very important that they are very soft for a smooth caramel.
2. Drain the dates and add in a high-speed blender together with coconut milk, vanilla, cinnamon and flaky salt. Blend until it is perfectly smooth and creamy.
3. Pour the filling into a small sauce pan and bring to a boil. Then reduce the heat to low and simmer for 2 minutes, whisking constantly, until the caramel is thick and brown. 
4. Remove from heat and add the lemon zest and half of the hazelnuts roughly chopped. Set aside.

Shaping the babka

1. Once the dough has doubled, transfer to a lightly floured surface and roll it out to a rectangle about 25 cm x 35 cm / 9 x 13 in, so that the short side is just a little longer than your loaf tin.
2. Spread the filling evenly over the dough, leaving a 1cm border. Sprinkle over the remaining chopped hazelnut and press them down gently.
3. Starting from the long side, tightly roll the dough into a log. Use a sharp knife to cut the log in half lengthwise, exposing the filling upward.
4. Starting at one end, pinch the ends together, then twist the two halves together into a braid, filling facing upward. Pinch together again at the end.  
5. Grease an approximately 25 cm x 11 cm / 9 x 5 in loaf tin and line it with baking paper. Place the braid in the loaf tin, gently squishing it to fit if need be.
6. Cover with a towel and leave in a warm place for about 30-40 minutes.

Baking the babka

1. When the dough has risen, preheat the oven to 340 degrees F (170°C).
2. Bake for 40-45 minutes or until golden brown and a toothpick inserted into the middle comes out clean. If the outside is browning too fast, turn down the oven to 320 degrees F (160°C) and cover the babka with a piece of aluminium foil. 
3. While the babka is baking, prepare the syrup by mixing together milk and maple syrup in a small bowl.
4. Remove the babka from the oven and immediately brush generously with the syrup. Leave the babka to cool in the tin for at least 20 minutes, then transfer onto a wire rack and leave to cool completely before slicing.