Is it possible to create a cone shaped plane?

I am doing an extrude cut down to surface.

The surface is a plane set at 2 degrees.

Except I need it to hold 2 degrees in all 360 degrees of rotation. This is why I need a cone shaped plane.

At 45 degree in the circle my ramped cut becomes 1.4 degrees.

See images one is ramp cut at 2 degrees around circle

Other image is the same ramp cut at 45 degree around circle.