Hello everyone,
how would you recommend to do something like in the attached picture?
Basically a roundish text with some sort of cracks and a different material inside.
I guess a way would be to use a bezier curve with Bevel depth, converting it into a mesh, sculpting the cracks, duplicating it to make a second object with a different material, using boolean to make the missing parts
Do you know better ways?
Well, I think it’s the best way to do it, I am not a professional in blender 
, but that’s the way I would have done it. 
You wouldn’t have to use booleans to remove sections - simply select and remove individual or groups of polygon faces. This will be much easier to maintain good topology.
This isn’t perfect, but it may give you some ideas.
I started with a bezier curve, beveled it, converted to mesh. I deleted the end faces, filled with an N gon, extruded and manually tapered the ends. I applied a subsurf modifier. Duplicated the object. Go into edit mode, select all faces and scale from median about 0.01. Delete large patches of faces. Use the knife tool to make them less grid like (shown in image on one opening). With all faces selected on the larger object, extrude (0 extrusion). Fatten (ALT S) the extrusion. Use dyntopo sculpting on the original object to make the dents. Use the smooth brush on the fattened larger object to smooth the knife cuts.
Of course, apply different material to each object.
