I am right there with you fighting same fight right now. I know this works, because I've lost my belly many times this way (I'm 42 with 3 kids), but it always comes back so I'm doing it again:
Best thing to burn away belly fat is ALL OVER muscle burning (especially largest groups like butt and thighs) to boost metabolism and burn calories (which is why merely laying on the floor and doing crunches does very little if anything without full work-out regime), but no matter what, your belly will go LAST. So if you have only 15 pounds to lose, it's ALL going to be in your belly....don't give up.
ALSO, fast walking. Long and far. My trainer at the gym, a svelt, wiry 50-something turned me onto that. So walk fast and long around neighborhood-or for at least 30mins on treadmill after workout.
To TARGET stomach muscles (to make them firm for when flub comes off-you cant' actually just burn the flub away this way) variations of planks are best. Holding yourself flat in push up position, etc. there are many different plank variations, ask someone at your gym or google videos: Planks for core.
But the overall calorie burn and fast walking are best to deflate belly.
Mine is huge right now from slacking.