Flooring Tile - Tile Backsplash in Bathroom

I have been researching on how to do my tile backsplash in my bathroom remodel. The vanity we bought has a raised lip on the back that is rounded so it would not look right at the transition from the vanity (sink) to a backsplash that is mounted on top of the drywall. Also, the mosaic tiles we are using does not come in a bullnose so I'm not quite sure on how to finish around the edge of it. My question is is it possible to make the backsplash flush with the drywall. Sort of like the backsplash is inlayed into the drywall. I was thinking of using a thin piece of cement backer the size of the backsplash and compensate with thinset to make the face of the tile flush with the drywall. Then the vanity could just butt up to the backsplash and a thin bead of silicone be applied to that seam. Can it be done this way? I haven't seen anything like this posted anywhere, so I'm guessing it's not the right way.

Not normally the way its done. How will you treat the edges of the cut drywall where it will meet the tile?

I assume your drywall is 1/2" thick. Normally, cement board for walls is 1/2" and cement board for floors is 1/4". I suppose you could use the 1/4" on a wall if you provided proper blocking in the walls to support all the edges of the cement board and adequate blocking/support in the field.

How thick is your tile? It'll have to be very thin as you will still only have 1/4" for tile and thinset or adhesive for it to be flush with the drywall. I dunno?

Schluter makes trim that can be used with tile if no bullnose is available. Take a look at their website. Some like the look of this trim and some don't.