Preheat the air fryer to 320 degrees F (160 degrees C) for 3-5 minutes.
Unroll the crescent dough and separate it into 8 triangles.
Add a few mini chocolate chips to the wide end of each triangle, then top with about 1 teaspoon of Nutella, keeping the filling away from the edges.
Roll each triangle from the wide end to the point and pinch the seams closed.
Brush both sides of each croissant with melted butter.
Place the croissants in a greased or parchment-lined basket in a single layer, leaving space between each. Cook at 320 degrees F for 6-7 minutes, turning halfway through.
Remove and cool on a wire rack. Repeat with any remaining croissants.
Melt the remaining chocolate chips in the microwave in 20-30 second intervals, stirring between each.
Drizzle the melted chocolate over the cooled croissants and serve.