No crank issue.

After replacing the head gasket on my 89 Escort and putting everything back together, I get in the car and try to start it. To my disappointment, the engine won't crank.

After the first attempt to crank the engine, I try to crank the engine again, but this time I have no power whatsoever, no idiot lights, no radio, no fuel pump running, etc. The only way I can get power again is if I disconnect the battery for about 5 seconds and reconnect. Then it's the same thing over again.

Anything come to mind what might cause this? Some short triggering a fail-safe thus cutting power? But where???

If you haven't done so yet, go back over the engine and check every electrical connector that you had unplugged and make sure they are all connected. Make sure your connections on the alternator and starter are tight. Test the battery and make sure that it is good.
I suspect something is not connected or your battery went kaput.