I would take a piece of paper and sketch out the letters with a pencil. I would then trace over that with a technical pen, adding the stippled shading, cracks, etc. I would then carefully erase any pencil.
I would then take a (digital) photograph of this drawing as tight as possible to fill the frame and bring it into photo editing software. I would use the transform tool(s) to straighten out any parralax problems caused by tilt and angle of the camera.
I would convert to greyscale and then ramp up the contrast and brightness such that there is very nearly only black and white. Clean up as needed, and then save as a non-lossy tiff.
I would open up a vector program, place the TIFF and then convert to vector using trace functionality. I'd delete the raster image, leaving onyl the trace. I would group the whole thing and add a white stroke to the outline of the group, I would place the group on top of a black square.
In the image below, I sketched the letters in 60 seconds with a Sharpie marker (so thicker lines and poor detail), but I think the result differs mainly in time and effort (and talent). It is a PNG here, but the source is 100% vector:
The following image is a very-much reduced in size version of the original snapshot. You can see some of the pencil lines in the final product. I did not erase and clean up the image as much as I might have for a real project: