Hi jorgy,
I think the picture is drawn by hand. Bt i reckon you could pull it off in moho.
Just draw whatever, fill it solid and double click on the layer (in the layer panel) to bring up its properties. Click the shadow tab and now click on the box saying "shading on."
You should now have control of which direction you want the shading and what colour. You can put the blur up to make a natural shade, or all the down to 0 to make a cartoon shade.
Theres also a drop shadow box there aswell...have a play around.