Add shadow around the masked region of a CALayer

I'm masking a `CAGradientLayer` with a `CAShapeLayer` in order to generate a bookmark that sits inside certain rows in my table. ``` CGMutablePathRef path = CGPathCreateMutable(); CGPathAddLines(path, NULL, (CGPoint[]){ CGPointMake(8, 0), CGPointMake(22, 0), CGPointMake(22, 22), CGPointMake(15, 16), CGPointMake(8, 22) }, 5); CGPathCloseSubpath(path); CAShapeLayer *mask = [CAShapeLayer layer]; mask.fillColor = [UIColor redColor].CGColor; mask.bounds = CGRectMake(0, 0, 30, 30); mask.path = path; mask.anchorPoint = CGPointMake(0, 0); CGPathRelease(path); CAGradientLayer *favoriteBadge = [CAGradientLayer layer]; favoriteBadge.colors = @[(id)[UIColor colorWithRed:.97f green:0.5f blue:0.1f alpha:1.f].CGColor, // orange (id)[UIColor colorWithRed:1.f green:.8f blue:0.f alpha:1.f].CGColor]; // yellow favoriteBadge.locations = @[@0.0, @1.0]; favoriteBadge.bounds = CGRectMake(0, 0, 30, 30); favoriteBadge.anchorPoint = CGPointMake(1, 0); favoriteBadge.position = CGPointMake(self.bounds.size.width, 0); favoriteBadge.mask = mask; // FIXME: This shadow is not being applied favoriteBadge.shadowColor = [UIColor colorWithRed:.97f green:0.5f blue:0.1f alpha:1.f].CGColor; favoriteBadge.shadowOpacity = 1.f; ``` This looks too flat, so I want to finish this off with a shadow around the shape itself. I've tried enabling shadow on the layer, but it doesn't seem to get applied. I assume it's being applied in the area that is not inside the shape. How can I add a shadow to the shape itself? I could copy the layer, darken it and offset its position by a few pixels, but that feels wasteful when CoreAnimation can probably do it more efficiently for me.