This golden cinnamon apple air fryer cake is the kind of dessert that makes your kitchen feel like a small, cosy bakery, turning one simple apple and a handful of everyday ingredients into something tender, fragrant and quietly luxurious. The batter is built on well‑whisked eggs, sugar and milk, which create a light, airy structure that bakes into a soft crumb rather than a heavy, dense cake. Flour and baking powder give the mixture just enough body and lift, so the cake rises gently and holds its shape while still feeling delicate when you cut into it. The apple is diced into small cubes and tossed with sugar and cinnamon, so every piece becomes a tiny pocket of sweetness and spice that melts slightly into the crumb as it bakes. Baking in the air fryer at a steady 160∘C keeps the cake moist inside while forming a gentle golden crust on top, giving you the effect of oven baking without needing a large appliance. A dusting of icing sugar at the end adds a soft, snowy finish that makes the cake look as inviting as it smells, perfect for serving with tea, coffee or a simple glass of milk.