American Authors isn’t a category at Molasses Books — it’s the latest Brooklyn band to hit it big. Their first single, “Believer,” spent 22 weeks on Alt Nation’s Alt-18 Countdown, while their second single, “Best Day of My Life,” just appeared in a trailer for The Delivery Man (in which Vince Vaughn wears a Warsaw t-shirt). You can hear both on their self-titled EP, out today.

Sounding like a more spirited (and less pretentious) version of Fun, the four-man group consisting of lead singer Zachary Barnett, guitarist James Adam Shelley, bassist Dave Rublin and drummer Matt Sanchez was signed to Island Records in January, and promptly embarked on a cross-country North American tour. They’re scheduled to play The Tonight Show With Jay Leno next Friday. We had a hungover chat with Barnett and Rublin last month after they played the Bunbury Music Festival.

BB_Q Where are you right now?

BB_A Zachary Barnett: Cincinnati. There’s a sweet rooftop pool up here, so we’re just kickin’ it. It’s not the worst thing in the world.

BB_QYou sound a little under the weather.

BB_A Barnett: I’m a bit hungover. We just played Bunbury with Fun, Tokyo Police Club, Walk the Moon, Youngblood Hawke and Tegan & Sara. There was a fan who reached out to us, saying, “My mom has terminal cancer, and what’s been getting her through these times is your song, ‘Believer.’” We Skyped her and said hi. At the festival he was Skyping with his mom during our sets – we played two sets, an acoustic set and a full band set – and from the stage we gave her a shout-out, we dedicated the song to her. He was a really sweet guy.

We were hanging out for Walk the Moon and Fun’s set, and he bought rounds of beer for everyone, one after the other, and then after that we went to this club in downtown Cincinnati, and there’s bottles of vodka and sparklers and champagne for champagne toasts.

BB_QSounds like a real rock star story. What has been your favorite part of the tour so far?

BB_A Barnett: We got to tour with The Mowgli’s at the beginning of the tour, and they were awesome. The festivals have been great. We’re looking forward to playing Lollapalooza and Mo Pop.

Dave Rublin: It’s been an awesome time for us because it’s our first time out where people actually know the music. It’s really cool to see people singing along and meeting all these new fans. It’s something we’ve always wanted.

BB_QThe band members originally met in Boston. What prompted the move to Bushwick?

BB_A Barnett: We all went to Berklee College of Music from ’06 to ’09, and we played in some other groups while at Berklee. We all moved to Brooklyn together three years ago, which is where we formed this band. Most of our friends were leaving Berklee, and they were either going to New York or L.A.; a lot of the people that we were writing music and recording with were moving to Bushwick, and our last summer in Boston, we were going back and forth between Boston and Brooklyn like two or three times a week. It was getting crazy. We figured we’d move the band to New York so we could be closer to the people we were working with. Now we all live in Bushwick together. It’s a great area, we really took to it.

BB_Q You were signed to Island Records in January. How did that feel?

BB_A Rublin: It was crazy. We went to the office, popped a bottle of champagne, signed the papers, and two minutes later we were in the van going on tour for the next three weeks. We didn’t really have much time to celebrate. It was straight to work, but that’s what we like to do anyway.

BB_Q There’s such a huge music scene in Brooklyn. Was it difficult to distinguish yourselves and make it big?

BB_A Barnett: We’ve been playing shows throughout NYC and Brooklyn, but what really what launched us to the next level was getting “Believer” in the hands of the DJs at Alt Nation. Alt Nation started spinning the song, and it caught on, and that’s what propelled things to the next level. Radio came unexpectedly, very quickly – that’s been crazy because we don’t even have an album out yet.

“Believer” wasn’t even finished when Alt Nation picked it up. They liked the song and wanted to play it, so we had to finish it really quickly, and the only other single we had was “Best Day of My Life.” Fortunately, both of those songs have reacted incredibly well. “Believer” has been picking up on radio, and “Best Day of My Life” has been picking up with TV and film. It’s been featured in a Lowe’s campaign, and it’s in a trailer for the new Vince Vaughn movie, The Delivery Man, and in a Hyundai commercial in the UK. It’s been very cool.

Rublin: I feel like in Brooklyn you can get so many things all at once, and it’s hard to focus on one thing because everyone in New York has ADD. We’ve been doing the same thing as a band for six years. We know each other really well, we know the sound we want, and we write to the best of our ability. People started taking notice and getting excited. The rest is history.

BB_Q Do you have any plans to record a full-length album?

Barnett: We’ve actually finished. Before we went out on tour we spent two months in Westchester recording our full-length album. We finished an EP and then did full-length. The EP will be out in August, and the full-length will be out after that, in the winter.

BB_Q Where are your favorite places to go in Bushwick?

BB_A Barnett: Roberta’s – great restaurant. Green Street Salads, off the Jefferson stop. Little Skips for coffee, and Pearl’s is the best bar.

BB_Q When is your next show in New York?

BB_A Rublin: It’s actually not scheduled yet. We’re going back out with The Mowgli’s, we’re going to a do a Midwest and Southeast run with them. They’re really cool. Eight people onstage, it looks like a fucking circus, but it’s really go