Carrie Underwood: To Have One's Birthday Cake ... And Eat It Too?

Carrie Underwood is celebrating her 33rd birthday while on the road, but a fan made sure she didn't miss out on the festivities.

Carrie was leaving a "BBC Breakfast" interview Thursday in London when a fan surprised her with a cake outside the studios. She seemed to love the sweet gesture ... but chances the country superstar actually bit into it are slim.

As they say ... never take candy from a stranger. Same goes for cake or pie.