Preheat the air fryer to 350°F (180°C). Grease and line a round 6-inch baking pan with oil and parchment paper.
Sieve all-purpose flour, baking powder, baking soda into a bowl and keep aside.
In another mixing bowl, add sugar, Greek yogurt, oil, and vanilla extract. Beat on low speed with a hand/stand mixer until just combined. Make sure the oil has blended well. Scrape down sides of the bowl and increase the mixer speed gradually. Beat for 5-7 minutes or until sugar has almost dissolved.
Add the dry ingredients mix to this in three parts. Use a rubber spatula to fold and mix the batter evenly. Don't worry if the batter looks slightly lumpy but don't overmix. If the batter feels too thick, add water one tablespoon at a time and adjust the consistency. This will depend on the thickness of the yogurt you use.
Transfer the batter to the prepared baking pan. Place the pan in the air fryer and bake at 350°F (180°C) for 30-35 minutes. It may take longer based on your air fryer capacity. Just bake it for 30 minutes and check every couple of minutes. Bake until it is firm to touch and a skewer/knife inserted into the baked cake comes out clean.
Remove from the air fryer and let cool for 20-30 minutes before unmolding. Layer and frost once cool or serve plain along with hot tea!