Babu, a 7½ years old child, reports with a fracture of
central incisor with an open apex, there is large pulpal
exposure. The treatment of choice is:
The Cvek Pulpotomy on Immature Permanent Teeth
Pulpotomy is an established technique for preserving vital pulp functions in immature teeth that have been subject to pulp-exposing trauma. Inflammation is confined to the surface 2 to 3 mm of the pulp, when it is traumatically exposed and left untreated for up to 168 hours. 
In a classic report, Cvek described a pulpotomy technique in which only the superficial 2 to 3 mm of hyperplastic inflamed tissue was removed with a water-cooled, high-speed diamond bur to place the wound in a healthy site. Hemostasis was then secured before capping with an appropriate material. 
Hemostasis was obtained with saline, and a pulp cap of calcium hydroxide was overlaid with a sealing coronal restoration.
Reference: Cohen Pathways of Pulp 11th ed page no e31
Smooth the edges and protect the exposed portion with ZOE dressing
Pulpectomy and calcium hydroxide dressing
Pulpotomy and calcium hydroxide dressing
Direct pulp capping and calcium hydroxide dressing