Bring a small pot of salted water to a boil. Add tofu; boil for 1 to 2 minutes. Drain.
Heat oil in a deep skillet or wok over medium-high heat. Cook and stir the chili bean paste until fragrant, about 1 minute. Add ginger and chile powder; cook and stir until fragrant, 1 to 2 minutes.
Stir tofu into the skillet; pour in enough water to cover. Bring to a boil. Stir in garlic scapes, soy sauce, and salt. Reduce heat and simmer until flavors combine, about 5 minutes.
Mix 1 teaspoon water and cornstarch together in a small bowl until cornstarch is dissolved. Pour into the skillet and stir gently until sauce thickens, 3 to 5 minutes. Sprinkle ground Sichuan peppercorns on top.