Preheat air fryer to 400°. On a lightly floured surface, unroll pizza crust into a 12-in. square. Cut into four squares. Layer ham, half of pear slices, walnuts and blue cheese diagonally over half of each square to within 1/2 in. of edges. Fold one corner over filling to the opposite corner, forming a triangle; press edges with a fork to seal.
In batches, arrange turnovers in a single layer in greased air-fryer basket; spritz with cooking spray. Cook until golden brown, 4-6 minutes on each side. Garnish with remaining slices.