In a food processor, pulse peanuts and pour some out for topping at the end. To the processor, add cilantro, garlic, ginger, vegetable oil, red pepper flakes, lime zest, lime juice, and brown sugar. Pulse until a coarse paste forms. Season with the soy sauce and sesame oil and pulse to combine.
Meanwhile, in a pot of salted water, cook pasta according to package instructions. Reserve 1/4 cup of the starchy salted cooking water and drain. In a large bowl, toss pesto with pasta while the pasta is still hot. Loosen the pesto with the reserved pasta water if necessary. Sprinkle remaining pulsed peanuts over pasta along with cilantro leaves.
Season shrimp lightly with salt and pepper and a drizzle of oil. Grill for about 1-2 minutes per side, or until they turn pink and the tails start to curl. If you have a lot of shrimp, you can cook them on wooden skewers that have been soaked for about 30 minutes, so they're easier to turn on the grill at the same time. This also makes a beautiful presentation. Serve with the cilantro pesto pasta.