I've been eying these Big Butt Baby Pants from Made by Rae for a while now... man, I should have downloaded this pattern much sooner! So cute!
The pants have an extra panel in the back to accommodate poofy diaper butt. If you're fancy, you can sew the pants with a contrasting fabric on that butt panel to maximize cuteness (I did not max out on cuteness this time... I wasn't sure you could take it after the baby romper, grandpa sweater and party hat).
I sewed one pair for baby Zoe (who is barely a baby anymore- she walks! she's 1!), made from a beautiful pink and green Amy Butler fabric that Jenny sent me. The smaller pair is for baby Alex, made from a cool batik (from which I also made a pillowcase). They have a bit of an MC Hammer feel to them, but a handsome boy looks good in anything, right? Plus, if his dad can pull off a singlet, Alex can pull these babies off.