David Nussbaum knows whatever he’s doing with “America’s Test Kitchen” is working when he attends events with hosts Bridget Lancaster and Julia Collin Davison. “You’d think I was with Michelle Obama and the ex-president,” he said. America’s Test Kitchen continues to grow, expanding from TV and magazines into podcasting, and attracting more than 400,000 paying subscribers to its website. Nussbaum spoke to host Kai Ryssdal about why the $10,000 spent developing each recipe on average is totally worth it; how he’s attracting a new and younger audience; and why he took the job at America’s Test Kitchen in the first place.