America’s Test Kitchen, an independent media company that puts out cooking television shows, magazines and cookbooks, has signed a deal to relocate its head offices to the Innovation & Design Building at 21-25 Drydock Ave. in Boston’s Seaport District.

The company will nearly double the size of its corporate office space with its relocation from 17 Station St. in Brookline to 52,856 square feet at the 825,552-square-foot, eight-story office complex…