Arrange a rack in the center of the oven; preheat to 375°. Place 3 layers of paper towels or a clean kitchen towel on a plate. Place tofu on towels and cover with another 3 layers of towels or another clean kitchen towel. Place a heavy can or skillet on top of tofu to press moisture out, pouring off excess water and replacing towels as they get soaked, at least 1 hour and up to 3.

Tear tofu into 1" chunks and transfer to a large bowl. Sprinkle with basil, black pepper, garlic powder, salt, and cayenne and gently toss with a rubber spatula until coated. Sprinkle with potato starch and gently toss until coated.

In a food processor or spice mill, pulse or grind breadcrumbs and onions until finely crushed and incorporated, 10 to 15 pulses.

Into a shallow bowl, pour milk. Transfer breadcrumb mixture to another shallow bowl. Dip each tofu piece into milk, then toss in breadcrumb mixture until coated. Transfer to a parchment-lined baking sheet. Spray tofu with cooking spray, turn over, and spray again.

Bake tofu nuggets, turning halfway through, until golden brown, 35 to 40 minutes.

Meanwhile, in a small bowl, combine ketchup, curry powder, Worcestershire sauce, and chili powder.

Season nuggets with a heavy pinch of salt and transfer to a platter. Serve with ranch and curry ketchup alongside.