How to extend a Control?

Was hoping to find some info but haven't been able to come up with anything. What I would like to do is Extend the RadzenPanelMenuItem so that I can add an option where it would display a Badge with a Numeric value just before the keyboard_down_arrow.

Any pointers to where I might find this type of info? Never done this before so not sure what to look for exactly.

I am afraid extending a Blazor component to override its rendering isn't easy (if at all possible). You have to reimplement it from scratch.

Ok, thx, I'd rather not do that.