Place the eggs in the air fryer and cook at 130°C (no preheating) for 10 minutes (you can also boil them). Transfer immediately to a bowl of ice-cold water, then peel and halve.
Cook the buckwheat noodles according to the packet instructions. Drain, rinse thoroughly under cold running water until completely chilled, then drain well.
Add the silken tofu, soya milk, toasted sesame seeds, peanut butter, soy sauce, maple syrup, garlic powder and a pinch of salt to a blender. Blend until completely smooth and creamy. Taste and adjust the seasoning if needed.
Divide the creamy broth between two serving bowls. Add the chilled noodles, cucumber ribbons and a halved egg to each bowl.
Drizzle over the sesame oil, sprinkle with sesame seeds and, if you like, finish with chilli oil and sliced spring onions. Serve immediately while everything is beautifully cold.