In a large bowl, mix wafer crumbs and butter. Press onto bottom and 2 in. up side of a greased 9-in. spring form pan.
Place chocolate in a small bowl. In a small saucepan, bring 1 cup cream just to a boil. Pour over chocolate; let stand 5 minutes. Stir with a whisk until smooth. Pour over prepared crust. Refrigerate 1 hour.
In a large saucepan, combine coconut milk, coconut and sugar; bring just to a boil. Strain through a fine-mesh strainer into a bowl, reserving strained coconut; return coconut milk mixture to saucepan. In a small bowl, mix cornstarch and 2 tablespoons water until smooth; stir into coconut milk mixture. Return to a boil, stirring constantly; cook and stir until thickened, 1-2 minutes. Remove from heat.
In a small bowl, whisk egg and egg yolk. Whisk a small amount of hot mixture into egg mixture; return all to pan, whisking constantly. Bring to a gentle boil; cook and stir 2 minutes. Remove from heat.
In a microwave-safe bowl, sprinkle gelatin over remaining 2 tablespoons cold water; let stand 1 minute. Microwave on high for 30-40 seconds. Stir and let stand until gelatin is completely dissolved, 1 minute. Whisk gelatin mixture into coconut milk mixture. Refrigerate, covered, 1 hour, whisking every 15 minutes.
In a large bowl, beat cream until stiff peaks form; fold into coconut milk mixture. Spoon reserved strained coconut into prepared crust. Spread filling over coconut. Refrigerate 6 hours or overnight before serving.