Britney Spears is proving a real treat by whipping up her "meanest" sandwich from her kitchen. The 39-year-old princess of pop yesterday thrilled her 29.5 million Instagram followers with a rare video. Mentions of food from the "Toxic" singer might be frequent, but videos showing the blonde prepping her eats are rare. Posting on Wednesday and shortly before parading around in a bikini and admitting she wants to get into "shape," the Grammy winner re-created a sandwich from her favorite NYC deli spot. Check it out below.