Preheat the oven to 400F.
Wrap the tofu in a paper towel and squeeze gently to remove some of the water, or use a tofu press for 5 minutes.
Cut into roughly ¾-inch cubes.
In a medium bowl, whisk together the oil and kosher salt.
Add the tofu, tossing to coat.
Add freshly ground black pepper, to taste, tossing again.
Transfer to a parchment paper lined sheet pan. Leave room between each piece of tofu.
Bake at 400F for 30-35 minutes, until golden and crisp, tossing the tofu halfway through.
Meanwhile, make the orange sauce. In a jar or small bowl, whisk together the orange juice, zest from the orange, brown sugar, rice vinegar, soy sauce, optional red pepper flakes, toasted sesame oil, grated ginger, and grated garlic.
In a separate jar, whisk together 1 teaspoon corn starch with 1 teaspoon water. Stir this into the orange sauce.
When the tofu is almost done, add the orange sauce to a sauce pot or wok.
Bring to a rapid simmer over medium-high heat. Reduce to a gentle simmer over medium-low.
Simmer, stirring frequently, until thickened enough to coat the back of a spoon without sliding off.
Transfer the baked tofu to the orange sauce, tossing to coat.
Serve over rice or noodles. Enjoy!