Cut tempeh into 2-inch cubes. Make sure they are in similar to size so it cooks evenly.
Add all of the ingredients for the marinade into a flat bowl and mix. Add the tempeh and gently stir to coat all sides. Let it marinate for 30 minutes or overnight in the fridge. After marinating, the tempeh will soak most of the liquid that is at the bottom.
Pre-heat air fryer to 350ºF (180ºC). Add ½ cup water to the bottom and lock the basket on top. Spray with cooking spray to prevent sticking. Add the tempeh in a single layer and bake for 7 minutes.
Using tongs, chopsticks or a spatula flip the tempeh cubes and bake for 7 more minutes (don't shake the basket, you'll spill the water). In the last 2-3 minutes. make sure to keep an eye on it as it tends to burn quickly.
Once the tempeh is golden brown with dark edges, remove it from the air fryer. If there is any marinade left in the bowl, brush it over the tempeh. If not, brush it with a little bit of sesame oil.
Serve while still warm with salads, pasta, noodles, or with wraps and sandwiches.