Well either this:
or this (middle one):
do pretty well. They don't split as well as an axe profile, but they do surprisingly well. Part of it it what hatchets do with mass and geometry, hawks do with speed. With the long (24" and 27") hafts, the speed of the bit is very high, and I had no trouble splitting 4" rounds of birch and pine with either. In fact, the faces slid right into the wood, and when the wood hit the cheeks, it just blew out. However, a weak swing would result in the 'hawk sticking.
So, if you go with a hawk, you have to understand what to get and how to use it. Most hawks seem to have too short a haft. On a light head like the trail hawk the two I posted are based on, 20" is enough, 24 is better. On a heavier head like, say a Fort Turner Iroquois, a 24-28" would be best. For splitting, swing hard and hit fast. For bucking, the first strike will stick, the next should be aimed to sever the wedge of wood, not drive as deep as you can. 'Hawks work more by pecking than by deep chops.
If you don't like how a hawk needs to be handled (they aren't for everyone) then a hatchet (I like the Snow & Neally Penobscot Bay) is the right idea.
OR. . .head over to Himalayan Imports and learn of the deliciousness of the kukri. . .