In a food processor, pulse the peanuts until coarsely chopped. Reserve 1/3 cup of the chopped peanuts for garnish. Continue pulsing the remaining peanuts until finely chopped. Add the vinegar, ginger, garlic, soy sauce, sugar, oil, 2 tablespoons of hot water and 1 teaspoon of salt to the peanuts and blend until the dressing is almost smooth, scraping down the sides of the bowl several times.