JUDY WOODRUFF: Walk through the aisles of any drugstore lately and it's quite clear the Easter season has become a critical part of the year for candy makers. But what's less obvious are some battles over the chocolate in those eggs and bunnies you may be buying.

Economics correspondent Paul Solman has the story, part of our ongoing reporting Making Sense, which airs every Thursday on the NewsHour.

PAUL SOLMAN: In New York City's Greenwich Village, British expat Nicky Perry and her husband, Sean Kavanagh-Dowsett, have recreated a little bit of the London they left behind, with two restaurants and a specialty shop.

And while they love living in the USA, they have got a beef with an all-American icon, Hershey's, which owns the U.S. license to the equally iconic British brand Cadbury.

NICKY PERRY, Owner, Tea and Sympathy: The problem is, Hershey has stopped us from selling our Cadbury's chocolate.

SEAN KAVANAGH-DOWSETT, Owner, Tea and Sympathy: We have got a huge corporation trying to ban the import of something that's so important to people.

NICKY PERRY: This is what I do for a living, and I am not going to be told I am not going to sell my chocolate.

PAUL SOLMAN: And where do you get the authentic Cadbury's now?

NICKY PERRY: If I told you, I would have to kill you.

PAUL SOLMAN: So, give me British Cadbury, or give me death?

NICKY PERRY: We will fight them on the beaches. We will never — listen, you don't mess with British people, because once you upset us, it is war all the way, and we do not give up.

PAUL SOLMAN: The British counterrevolution began earlier this year, when Hershey's successfully sued a New Jersey company that was importing the British original, and distributing it not just to small specialty shops, but to large retailers.

NEHAL PATEL, Cadbury Marketing Director, The Hershey Company: We bought this trademark in 1988 for $300 million, and we own this trademark, and we own every aspect of it.

PAUL SOLMAN: Nehal Patel is the Cadbury brand manager for Hershey's.

NEHAL PATEL: Cadbury is a very important brand to The Hershey Company. It is a brand that we have grown to be an iconic Easter brand. We're going to sell 50 million Creme Eggs this year.

NARRATOR: Everyone wants to be the Cadbury bunny, because only he brings delicious Cadbury Creme Eggs.

PAUL SOLMAN: And 50 million is hardly chicken feed. Easter has the largest share of seasonal candy sales in the U.S., over $2.3 billion last year, topping Valentine's Day, Christmas, even Halloween. So given the fact that Hershey's Cadbury brand generates over $200 million a year in sales, why doesn't Tea and Sympathy simply stock the American-made version?

NICKY PERRY: We have been here for 20 years in this shop selling Cadbury's chocolate, not just to British people, but to Americans, who all know that the English Cadbury is way, way better than the Hershey facsimile.

PAUL SOLMAN: And customers here concur.

DEBRA BROTHERSON, Chocolate Buyer: I prefer it to the American because it's much smoother and tastier.

MARK ALLEN, Chocolate Buyer: I wouldn't buy the American version because it's not — to me, it's not the same thing.

DANIEL NEIDEN, Chocolate Buyer: It's not the same recipe. It doesn't taste the same. Unfortunately, it tastes just like Hershey's.

SEAN KAVANAGH-DOWSETT: Chocolate is such a strange thing. It triggers memories and emotions and feelings of well-being, yummy warm feelings.

PAUL SOLMAN: And why so yummy?

SEAN KAVANAGH-DOWSETT: The number one ingredient in English Cadbury's is milk. The number one ingredient in the American version of Cadbury's is sugar.

PAUL SOLMAN: Well, so much for the British side of the story.

But what do they say in the American city synonymous with chocolate, Hershey, Pennsylvania? That the recipes are nearly identical.

Jim St. John is Hershey's master chocolatier.

JIM ST. JOHN, Vice President for Chocolate Product Development, The Hershey Company: The milk, sugar and chocolate were all cooked together in the British Isles. So we're buying their stuff. It's their specification. It's what the Cadbury family first brought over here to the States.

PAUL SOLMAN: But, on the package, it says milk first on the English Cadbury and sugar first on the American Cadbury.

JIM ST. JOHN: Yes, that's true. And that's because the rules around labeling are different in England than they are in the United States. They count all the milk, including the water that was in the milk. In the United States, we can't count the water.

PAUL SOLMAN: But there is one crucial difference, and why Hershey's had to change the recipe to comply with U.S. federal regulations.

JIM ST. JOHN: What they sell in England can't be sold in the United States and be called milk chocolate, because they add fats other than cocoa butter. They're using palm and shea oils. We're only using cocoa butter.

PAUL SOLMAN: So, palm oil, shea oil, that's not part of what's considered chocolate in the United States, according to FDA standards?

JIM ST. JOHN: Right. Right. So, that is not a chocolate in the United States.

PAUL SOLMAN: So those remembrances of warm feelings past are triggered by palm and shea oils?

Well, even so, why not let the little store in Greenwich Village sell the original Cadbury chocolate? What's the big deal to Hershey?

NEHAL PATEL: Our intention is not to go after the smaller shops, but when we started seeing this formula in the mass retailers, that's when we got concerned, because it's a slippery slope.

PAUL SOLMAN: But, say the Brits, it's not just about Cadbury. Hershey's has successfully blocked other British brands, like Toffee Crisp, made by Nestle in the U.K., because its wrapper, says Hershey's, looks like their Reese's Peanut Butter Cup.

And England's Yorkie bar can no longer be imported because its name sounds like Hershey's York Peppermint Pattie.

NARRATOR: Get the sensation.

PAUL SOLMAN: So now here is a Yorkie bar from England. And you all won't allow this because the name is too similar to a York Peppermint Pattie?

JIM ST. JOHN: We own the name York. York Peppermint Pattie started out in York, Pennsylvania.

SEAN KAVANAGH-DOWSETT: York, Yorkshire, you know, War of the Roses.The grand old duke of York, he had 10,000 men. He marched them up to the top of the hill, and they wouldn't eat Cadbury's again.

PAUL SOLMAN: So, as Easter nears, where are we? Cadbury U.S. vs. Cadbury U.K., a tempest in a tea shop, perhaps, but when it comes to Toffee Crisps and the Yorkie bar, non-nationalist observers, like lawyer and Tea and Sympathy customer Yetta Kurland wonder, if Hershey's isn't being just a tad overprotective of its intellectual property.

YETTA KURLAND, Lawyer: We want to recognize and respect licenses and contracts between companies, but we ought to be careful that we're also letting people engage in commerce and run their businesses.

PAUL SOLMAN: Reporting for the PBS NewsHour from New York, this is economics correspondent Paul Solman.