Bake the potato in foil at 375° F until soft, about 45 minutes. While still hot, pass it through a potato ricer into a mixing bowl to remove the skin. Measure the amount of potato you need based on the scale of the recipe you are making, add the strained ricotta while still warm, and sprinkle the mixture with the flour and salt. Mix gently to combine, and roll the mixture into ¼ inch logs about 12 inches in length using a lightly floured work surface. Cut into ½-inch rectangles, place gently onto a floured parchment-lined sheet pan, and refrigerate until ready to cook.
Bring 6 quarts of heavily salted water to a rapid boil. Cut the Brussels sprouts into fourths and drop them into the boiling water. Blanch in boiling water for 3 minutes until soft. Remove and place in a bowl of ice water to shock and stop cooking, then drain and reserve.
Meanwhile, bring a sauté pan to high heat, and once the sprouts are dry, add olive oil and sauté them until slightly brown; add the bread crumbs, sauté 2 minutes more, then add the butter and let brown for 1 minute and take off the heat.
In a medium saucepan, sweat the shallot and black truffle in a little olive oil over low heat for 3 minutes. Add the white wine, reduce until the shallots and truffles are glazed, then add the heavy cream and simmer over medium heat for 2-3 minutes or until the sauce is just slightly thick in consistency.
Drop the gnocchi in the same pot of water used to cook the Brussels sprouts, making sure that the water is boiling rapidly. Cook for 1-2 minutes or until the gnocchi rise to the top of the water. Remove with a strainer and add to the cream mixture, stirring and serving.
Top with the Brussels sprouts and grated Parmesan.