Prep your pan and air fryer: Lightly grease a 7-inch round cake pan with butter or oil spray. Line the bottom with a parchment circle if you have one. Preheat your air fryer to 320°F (160°C) for 3–5 minutes.

Make the caramelized topping: Pour 2 tablespoons melted butter into the pan and swirl to coat the bottom. Sprinkle 1/2 cup brown sugar evenly over the butter.

Arrange the fruit: Lay pineapple rings over the sugar layer in a single snug layer. Place a cherry in the center of each ring if using. If there’s space, tuck small pineapple pieces around the edges.

Mix the dry ingredients: In a bowl, whisk together 1 cup flour, 1/3 cup sugar, 1 1/2 teaspoons baking powder, and 1/4 teaspoon salt.

Mix the wet ingredients: In another bowl, whisk 1 egg, 1/2 cup milk, 2 tablespoons melted butter, 1 teaspoon vanilla, and 2 tablespoons pineapple juice (if using) until smooth.

Combine batter: Add the wet mixture to the dry and whisk gently just until no dry streaks remain. Don’t overmix. The batter should be pourable but not thin; add a teaspoon of milk if it seems too thick.

Assemble: Pour the batter over the pineapple layer and smooth the top with a spatula. The pan should be filled to about two-thirds full to allow for rise.

Air fry: Place the pan carefully in the basket. Cook at 320°F (160°C) for 20–26 minutes, or until the center springs back lightly and a skewer comes out clean. If the top browns too quickly, tent loosely with foil during the last 5–7 minutes.

Cool briefly and invert: Let the cake rest in the pan for 10 minutes. Run a thin knife around the edge. Place a plate over the pan, then flip carefully. Lift the pan to reveal the glossy pineapple top.

Serve: Let it cool another 10–15 minutes before slicing so the topping sets slightly. Serve warm or at room temperature, plain or with a dollop of whipped cream.