Culling Texture For blocks (mushroom block)

Hello, I've had issues being able to make big mushrooms with custom changing textures, as far as i know and seen there's no option for a block to have a multi-texture thing where when you place a block besides it and remove that block, it changes its texture to the inner one. I'm surprised there's not even an option for that considering how long mushrooms have existed in the game for. 

As you can see this is what the inner texture of a mushroom block looks like, If there was a way to accomplish similarly, that'd be great!!!