Toast the hazelnuts in a skillet over medium heat until the skin starts to release. Let them cool and rub them gently in a towel to make sure that all skin was removed.
Mix all the ingredients. Make sure that all flour is hydrated.
Let the dough bulk ferment for 4 hours at a temperature of 72°F/22°C.
Oil a bread pan, about 10"x5"x2.5"/26x11x6.5 cm in size, and distribute the dough into it.Smooth the surface with a wet spatula.
Let the dough proof for about 2.5 hours at 72°F/22°C, or until it has risen about 20-30% of its initial volume.
Preheat the oven to 430°F/220°C. Bake the bread for 60-70 minutes, or until the inner temperature reaches 215ºF / 100ºC. It may be necessary to cover the loaf for the last 15 to 20 minutes to prevent the loaf beeing burnt on top.
Let the bread cool in the form until you can handle it. Take the bread out of the pan and place it in the oven again for about 5 to 10 minutes.