07/12/2011 AT 06:00 AM EDT
played a pastry chef in her hit comedy Bridesmaids
– and she looked right at home enjoying a chocolate croissant and a cappuccino at Plaisir Bakery in West Hollywood. "She was all smiles, and she took her time deciding on what she wanted to go with her coffee," an onlooker says. "You could tell she was just enjoying a relaxing, low-key day."