This Build is meant for Straight AP and Straight damage on your target, causing it to release heavy damage. I've been playing annie with this build for about a good three months and havent lost a single match on Ranked and Unranked Matches.. The offensive is really high with this character but the team fight is the question.

I always Pick Doran's Ring before the game starts. Ever since I know how to play annie, It easy to farm with her. Right when i reach level 6 or 7, i Atleast have enough to buy Needlessly Large Rod. Or if i stay in lanes longer, i could even buy boots of speed. But it all depends on your enemy. Annie needs gold, and Gold = Victory. Once laning phase is over, you should have barely enough for another needlessly. If not, its fine...Depending how the fight goes, you might find yourself in a very slow situation. If your feeling very slow and can't survive or gank, you can always buy sorcerers boots. but it'll take longer for you to get the 2nd needlessly large rod.

Once you get the 2nd Needlessly large rod, you have two options:

If your Team is winning and you know they're winning, Go with the DeathCap.

If your not too sure and seems like they're focusing on you (Annie) get Zhonya's Hourglass.
It will increase your armor and has the ability to put you in a invunerable spot for 2 minutes.

once you get the best AP items, focus on blues and dragons with the team mates. The Blue buffs will help you last longer, since you have NO MANA items what-so-ever!

Your next item will be your Extra Damage and Cool Down Reduction. Deathfire Grasp does alot, i mean, ALOT of damage since you have the 2 powerful AP items in the game.

And your last item is Morello's Tome book. Makes your stun ALOT Faster.
More Stun = Possible Penta Kill.

If the game is still going and you have full build, try selling your Dorans ring and get Lich Bane.

Well, that settles it. Enjoy and GL on your game.