The Basic Sequence 

1.  Create your text in the default XY plane. Select all the text.

2.  Convert to Vector. (Command line - C2V)

3.  Select all the Vector Text and MakePlane (Command Line - MP). All the outlines including the interior islands are converted to planes in one step.

4. Select all the Planes and Extrude some Z distance. All the planes including the interior islands are extruded in one step.

5.  Solid subtract the interior solids from the exterior solids. Work these per letter.  Best if you work in wire frame mode. (Specifically for the letters A,B,D,O,P,Q,R).