While the pasta cooks, whisk together the peanut butter, soy sauce, ginger, garlic, sesame oil, maple syrup, sriracha, red pepper flakes, and water to make the peanut sauce. Transfer to a small saucepan over medium heat and cook for a minute or two, just until the garlic softens.
½ cup peanut butter, ¼ cup soy sauce, ½ tablespoon ginger, 1 clove garlic, 1 tablespoon sesame oil, 1 teaspoon maple syrup, ½ teaspoon sriracha, ½ teaspoon crushed red pepper flakes, 3 tablespoon water