Cook the ramen noodles according to package directions until tender. Do not overcook.
Reserve about 1/4 cup of the hot cooking water, then drain the noodles well.
While the noodles cook, whisk together the peanut butter, soy sauce, rice vinegar, brown sugar, sesame oil, ginger, garlic, and chili garlic sauce in a medium bowl.
Add 2 tablespoons of the reserved hot noodle water to the sauce mixture and whisk until the sauce is smooth and creamy.
Add the drained, hot noodles directly to the bowl with the peanut sauce.
Toss the noodles thoroughly until they are completely coated with the thick sauce.
Serve immediately, garnished with sliced green onion and chopped peanuts.
Notes
For a thicker sauce, reduce the amount of reserved water you add.
You can substitute almond butter for peanut butter if desired.
Add a splash of lime juice to the sauce for extra brightness.