Bring a large pot of salted water to a boil over high heat.
In a large, heavy skillet heat the cream, zests, honey, and salt over medium heat, being careful not to boil the cream. Stir occasionally for about 4 minutes.
Meanwhile, add the pasta to the boiling water and cook until tender but still firm to the bite, stirring occasionally, about 2 to 3 minutes. Drain the pasta. Add the pasta and the lemon juice to the skillet with the cream sauce. Toss to combine.
Place the pasta in serving dishes. Using a vegetable peeler, shave chocolate directly on top pasta. Sprinkle with hazelnuts. Serve immediately.
Place the flour in a food processor. In a small bowl, lightly beat the eggs. Add the salt and olive oil to the eggs and stir to combine. Add the egg mixture to the food processor. Pulse to combine the ingredients, scraping down the sides once or twice. Continue, with the machine running, until the liquid is evenly distributed, about 1 minute. The dough should stick together if pinched between your fingers. The dough will be cornmeal-yellow in color. Some of the dough will be sticking together, but it will not form a single ball.
Turn the dough out onto a lightly floured surface. Press the dough into a ball and knead gently until the dough is smooth. Cover with plastic wrap and let rest for 30 minutes.