Whisk together the soy sauce, toasted sesame oil, rice vinegar, maple syrup, white pepper, and garlic powder in a small bowl. Set aside.
Heat the sesame oil in a large wok or skillet over medium-high heat. Add the diced onion and cook for 2 to 3 minutes until softened. Stir in the garlic and ginger and cook for about 30 seconds until fragrant.
Add the carrots and cook for 3 minutes, then stir in the peas and edamame. Cook for another 2 to 3 minutes until the vegetables are heated through.
Add the chilled rice, breaking up any clumps with a spatula. Stir-fry for 3 to 4 minutes until the rice begins to crisp slightly.
Pour the prepared sauce over the rice and toss well so every grain is evenly coated. Continue cooking for another 2 minutes.
Fold in most of the sliced green onions and stir everything together.
Taste and adjust with additional soy sauce if needed.
Serve immediately, topped with toasted sesame seeds, extra green onions, and a drizzle of sriracha or chili crisp if desired.