Preheat the oven to 350. Lay the nuts on a rimmed cookie sheet and toast them for 10 minutes. Rub off the skins the best you can, then put the nuts in the boiling water for about 30 minutes. Strain the water, leaving behind hazelnut debris and skins. Put the nuts aside to dry.
Check the temperature of the hazelnut water and make sure it's somewhere around 110 degrees. If it cooled down, heat it a little. If it's still too hot. let it cool. Put it in the bowl of the stand mixer. Add the yeast and sugar and let stand for 5 minutes to proof the yeast. Add the salt and 2 cups of flour. Stir. Continue adding flour and until you have a not-too-sticky dough.
Attach the dough hook to the mixer and knead for 8 minutes. Dough should clear the sides of the bowl as it kneads. Let stand stand 10 minutes, then stir in the hazelnuts. Put the dough in a greased bowl (or just leave it in the stand mixer bowl), cover and let rise for one hour or until doubled in bulk. Punch down the dough.
Grease a 9x5 inch loaf pan and line with a strip of parchment (if you have some). Put the dough into the loaf pan, cover with an oily piece of plastic wrap and let it rise for another 40 minutes or so. It should come up near the top of the pan. It doesn’t rise much in the oven, so do let it rise long enough.
Bake at 375 degrees for about 35 minutes or until bread sounds hollow when tapped. Let cool in the pan for 30 minutes, then turn from pan and let cool.