ここで私がしたこと(それは私にかなりのグーグルを要しました)
実装ファイル内
-(id)init
{
    self = [super init];
    self.isTouchEnabled=YES;
    if (self != nil) 
    {        
    }
    return self;   
}
//pinch recognising
-(void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    NSSet *allUserTouches=[event allTouches];
    if(allUserTouches.count==2)
    {
        UITouch* touch1=[[allUserTouches allObjects] objectAtIndex:0];
        UITouch* touch2=[[allUserTouches allObjects] objectAtIndex:1];
        CGPoint touch1location=[touch1 locationInView:[touch1 view]];
        CGPoint touch2location=[touch2 locationInView:[touch2 view]];
        touch1location=[[CCDirector sharedDirector] convertToGL:touch1location];
        touch2location=[[CCDirector sharedDirector] convertToGL:touch2location];
        ball.position=touch1location;
        newBall.position=touch2location;
        float currentdist=ccpDistance(touch1location, touch2location);
        oldDist=currentdist;
    }
}
-(void)ccTouchesMoved:(UITouch *)touch withEvent:(UIEvent *)event
{
    NSSet *allUserTouches=[event allTouches];
    if(allUserTouches.count==2)
    {
        UITouch* touch1=[[allUserTouches allObjects] objectAtIndex:0];
        UITouch* touch2=[[allUserTouches allObjects] objectAtIndex:1];
        CGPoint touch1location=[touch1 locationInView:[touch1 view]];
        CGPoint touch2location=[touch2 locationInView:[touch2 view]];
        touch1location=[[CCDirector sharedDirector] convertToGL:touch1location];
        touch2location=[[CCDirector sharedDirector] convertToGL:touch2location];
        float currentdist=ccpDistance(touch1location, touch2location);
        if (oldDist>=currentdist) 
        {
            //[spriteToZoom setScale:spriteToZoom.scale-fabs((oldDist-currentdist)/100)];
            [ball setPosition:touch1location];
            [newBall setPosition:touch2location];
            NSLog(@"pinch out");
        }
        else 
        {
            //[spriteToZoom setScale:spriteToZoom.scale+fabs((oldDist-currentdist)/100)];
            [ball setPosition:touch1location];
            [newBall setPosition:touch2location];
            NSLog(@"pinch in");
        }
    }
}