In a blender, combine the ginger, soy sauce, sesame oil, peanut butter, sugar, vinegar, rice wine, garlic, sesame paste, shallot and 3 tablespoons of the peanut oil and puree until smooth. Transfer the sauce to a bowl and refrigerate for 45 minutes.
In a large pot of boiling water, cook the noodles until al dente. Drain and rinse under cold running water until chilled. Shake out the excess water and blot dry; transfer the noodles to a bowl and toss with the remaining 2 tablespoons of peanut oil. Add the peanut-sesame sauce and toss well to coat. Garnish with the cucumber and scallions and drizzle with Ma La Oil, leaving the solid spices behind.
Roasted peanut oil, as opposed to neutral peanut oil, smells richly nutty. Boyajin’s Fragrant Peanut Oil is available at specialty markets and from mingspantry.com.