Whisk peanut butter, soy sauce, rice vinegar, honey, ginger, garlic and sesame oil in a large bowl until smooth. Stir in hot sauce to taste. If very thick, thin with a little water.
Reserve 3–4 tablespoons of dressing in a small bowl. Add a splash of water or soy sauce to make it pourable; set aside.
Halve cucumbers lengthwise, then slice each into six long wedges. Chop into 1½" diagonals and toss with the larger portion of dressing. Let sit 5 minutes.
While cucumbers rest, wrap tofu in paper towels and press gently to remove excess moisture. Slice into 8–10 slabs, dust lightly with cornstarch, then pan-sear in 1 tablespoon oil over medium-high heat until golden, 3–4 minutes per side.
Layer half the tofu on a platter, drizzle with half the reserved dressing. Pile half the dressed cucumbers over top. Repeat with remaining tofu, dressing and cucumbers.
Scatter chopped peanuts and scallions over the stacked salad. Finish with toasted sesame seeds and an extra drizzle of chili crisp if desired. Serve immediately.