In a mixing bowl, whisk together gochujang, soy sauce, sesame oil, maple syrup, minced garlic, grated ginger, rice vinegar, water, and cornstarch until smooth and combined; set the sauce aside.
Press the tofu to remove excess water, then cut into 1-inch cubes.
Heat 2 tablespoons vegetable oil in a large skillet over medium heat until shimmering.
Add the tofu cubes in a single layer and fry, turning occasionally, until golden brown on all sides, about 5–7 minutes.
Pour the prepared sauce over the fried tofu and stir gently to coat all pieces.
Cook the tofu with the sauce, stirring occasionally, until the sauce thickens and becomes glossy, about 5–8 minutes.
Transfer to a serving dish and garnish with sliced green onions and toasted sesame seeds before serving.