is it possible to add a reference from one project to another and at the same time visa versa. From A to B and from B to A?

If you are asking if Visual Studio will do if for you no. It won't and doesn't support a "circular" reference.

you can alternatively achieve this through reflection. But you won't have all the neat perks visual studio would normally give you with a design time reference.

I would suggest if its possible to redesign 2 projects to not need such a thing.

Diamonddrake is right here. Why do you want to add a circular reference though? I thought I had cases in the past where it would be useful but after thinking about it I was always able to come up with another library design that would serve the same purpose and make visual studio happy :)