Score 2 touchdowns in one period.

The best time to get this is at the beginning of a game in Easy mode. If you do not score on your first drive, restart the game and try again. And then, once you score the first time, either hold them on Defense OR if they get a break away run/pass, let them score. Then you will get the ball back with plenty of time to score again. And make sure you pick plays as fast as possible, because the clock will be running in between plays.