Mix lukewarm soy milk, sugar, and yeast in a little bowl and leave it for 5 minutes until foaming. Add it with the flour, salt, vanilla extract, and lemon zest to your kitchen machine. Knead for 5 minutes at a low-speed.
Add the margarine and knead for another 10 minutes at medium speed, until you have a soft dough which comes away easily from the bowl. Cover with a damp kitchen towel and leave to rise for 1.5 hours at room temperature.
Fill & Form
Meanwhile, roast the hazelnuts in a pan for 5 minutes until golden. Chop them roughly.
Roll out the dough on a floured surface into a long rectangle (10"x16" | 25cm x 40cm). Spread evenly with Nutella and leave ~0.5"/1cm border uncovered. Top with the roasted hazelnuts.
Tightly roll it into a log, cut lengthwise in half, and twist into a braided bread.
Carefully transfer the braided bread into a with parchment paper lined loaf pan (US: 10″x5″ | Europe: 25cm). Cover with a damp kitchen towel and let it rise for another hour at room temperature (or overnight in the fridge).
Bake: Preheat your oven to 395°F/200°C. Brush the bread with the bread wash and bake it for 30 minutes in the oven until golden.
Let it cool down for 15 minutes on a wire rack before slicing.
Notes
You can use any unsweetened plant-based milk for this recipe. If you only have sweetened milk, use less sugar for the recipe.
Don't worry if the bread doesn't fill the loaf pan entirely, it will rise during baking.
The bread tastes best when fresh, but you can store it covered for up to two days at room temperature or freeze it up to 3 months.
Vegan version: Use plant-based chocolate spread instead of Nutella.