Is there a simple method for adding a layer that conformally coats the layers below it?

What I would like is to draw a 2D rectangle on the 1st layer and then extrude it with a side taper angle of 45 deg.

I then want to draw a larger 2D square on a new 2nd layer and have its area surround around the rectangle's.

When I extrude the square I want the extruded surface to reflect the fact that in some areas of the box the 3D rectangular shape is beneath it.

Thanks