Spray a mini loaf pan generously with nonstick cooking spray, getting into the corners.
In a mixing bowl, cream the butter and sugar until pale and fluffy, about 2 minutes.
Mix in the eggs and vanilla extract until fully combined.
Add the flour, baking powder, salt, sour cream, and milk. Mix just until no dry streaks remain — do not overmix.
Gently fold in the raspberries with a spatula, five or six strokes.
Pour the batter into the prepared pan until it is about two-thirds full.
Set the pan in the air fryer basket or on the tray. Air fry at 330°F for 12 minutes on the air fry setting.
Insert a toothpick into the center. If it comes out clean, the bread is done. If not, continue air frying in 5-minute intervals, checking each time.
Let the loaf rest about an hour before slicing. Serve and enjoy.