Ezreal

Bottom

Money in the Bank

Money-making and accelerated item scaling.

Inspiration

Creative tools and rule bending

Kleptomancy

Your first attack after using an ability on champions grants gold and sometimes consumables.
Magical Footwear

You get free boots at 10 min. but you cannot buy boots before then. These boots give additional MS. For each takedown you acquire the boots 30s sooner.
Biscuit Delivery

Get a free biscuit every 3 minutes, until 12 minutes. Biscuits heal and permanently increase your max mana.
Cosmic Insight

+5% CDR
+5% Max CDR
+5% Summoner Spell CDR
+5% Item CDR

Sorcery

Empowered abilities and resource manipulation

Manaflow Band

Hitting enemy champions with a spell grants maximum mana.

After reaching 250 mana, Manaflow Band restores 1% of your missing mana every 5 seconds.
Gathering Storm

Gain increasing amounts of AD or AP, Adaptive over the course of the game.

WhyKleptomancy

Kleptomancy procs exactly like Sheen resulting in Ezreal being one of the biggest abusers of the proc though the use of [Q].

The consistent influx of both Mana and Health potions saves you a lot of money over the course of the game paired with a significant income from the occasional "Sacks of Gold" proc.

WhyMagical Footwear

Magical Footwear combined with Klepto is designed to skyrocket you ahead in item efficiency for an extremely powerful mid-game.

WhyBiscuit Delivery

Klepto potions plus Biscuits means you shouldn't have to purchase many potions at all with earned gold. The extra bit of maximum mana and mana sustain is also important for dishing out damage.

WhyCosmic Insight

Ezreal probably loves CDR more than any other AD Carry does. CDR means more survivability and way more damage. The slight Summoner cooldown also provides safety in your weak early game.

If you're looking to build Iceborn Gauntlet instead of Tri-Force then Approach velocity is an interesting choice here to further chase down your target.

WhyManaflow Band

Manaflow band grants massive early game lane sustain when paired with the potions from Klepto. In the later points of the game when you have a stacked tear, Manaflow will refund massive amounts of mana.

WhyGathering Storm

Gathering Storm is your late-game insurance policy. Since you'll be spending the majority of your early game surviving and poking with [Q], the early damage isn't as necessary.