So, here is the other card I made for my friend for her baby showers. This one turned out soooo cute! I made something similiar to an explosion box only with one layer and used it as a "unfolding card box".
I created a simple box using two 9"x9" sheets of cardstock (one for the base and one for the top). You score the paper on the both sides at 3" and 6". You than cut the 4 corner pieces off. Fold in and this makes the unfolding box base. For the top I cut out a 5 1/6" inch square (this will create a top that is 3 1/6" with a 1" lip all the way around).