Press the tofu (recommended): Wrap in a clean towel and press under a heavy pan for 15–20 minutes. Pat dry.
Tear the tofu into bite-sized chunks and toss with cornstarch until evenly coated.
Heat olive oil in a large nonstick skillet over medium-high heat. Add the tofu and cook, stirring occasionally, until golden brown on all sides, about 12–15 minutes. While the tofu cooks, prepare the orange sauce. In a bowl or measuring cup, whisk together orange juice, orange zest, soy sauce, vinegar, honey, garlic, and ginger (if using).
Pour the orange sauce over the tofu and bring to a gentle boil. Toss to coat.
Reduce the heat to low and simmer until the sauce thickens and coats the tofu, about 15–20 minutes. The glaze is ready when it coats a spoon and has reduced by about half.
Season with salt and pepper to taste. Serve over rice or noodles and top with sesame seeds, chopped green onion, red pepper, and cilantro (optional).