Preheat oven to 400°F/205°C. Line a baking sheet with parchment paper and set aside.
Drain and press firm tofu. Toss with oil and soy sauce. In a separate bowl, mix your white or black pepper and cornstarch. Toss in tofu and generously coat with dry mixture. Bake in oven for 30 minutes or until crispy (if your tofu is too wet, it won’t crisp up!)
Mix the gochujang, water, soy sauce, mirin, sesame oil, grated ginger, and minced garlic in a shallow saucepan and simmer. Create a cornstarch slurry with 1 tablespoon cornstarch and 2 tablespoon water. Pour into gochujang mixture and stir constantly until the sauce thickens.
Throw the baked tofu in the sauce. Toss lightly so all the tofu is evenly coated.
Serve with white rice and top with some chopped scallions and white sesame seeds.
Notes
Remember, the key to crispy and flavorful tofu is to drain and press your tofu. You want to squeeze as much liquid out as possible.