Preheat an air fryer to 320 degrees F (160 degrees C). Spray a small fluted tube pan with cooking spray.
Beat sugar and butter together in a bowl using an electric mixer until light and creamy. Add egg and jam; mix until combined. Sift in flour, cocoa powder, and salt; mix thoroughly. Pour batter into the prepared pan. Level the surface of the batter with the back of a spoon.
Place pan in the air fryer basket. Cook until a toothpick inserted into the center of the cake comes out cleanly, about 15 minutes.
