Source: Miley Cyrus & Liam Hemsworth Are Back Together

Liam Hemsworth and Miley Cyrus in L.A. on Sept. 11

Are they back on – or just hungry?

After announcing their split in August, Miley Cyrus reunited with Liam Hemsworth Saturday in Los Angeles, and a source tells PEOPLE that they are, indeed, dating again.

On Saturday, the two spent some time at Cyrus's Toluca Lake, Calif., house before running errands, with Cyrus behind the wheel. First, there was a stop by Panera Bread in Studio City, where Hemsworth, 20, picked up food to-go. Cyrus also grabbed some drinks at a local Starbucks drive-through.

"Miley and Liam kept smiling and seemed to really enjoy their afternoon together," an eyewitness says of the two. "They acted like they had missed each other, kept chatting and seemed to be catching up. They definitely seemed like a couple again."

Cyrus, 17, has been in Europe filming her new movie, LOL: Laughing out Loud.

"Since Miley returned to L.A. from Europe earlier in the week, she has acted a bit tired and worn out," the eyewitness says. "With Liam back in her life on Saturday, she acted totally different and, instead, seemed very happy. It looked like Miley and Liam had never been apart, and they were back into their old routine."