From Homestar Runner Wiki
Mrs. Bennedetto is Marzipan's microwave. She is Frank Bennedetto's mother, as noted in the DVD commentary for army. Homestar comes to her to settle a debt of five bucks left by Frank. She is also a member of Pile of Electronics State, as shown in the email "mascot."
She has buttons for Power, Frozen, Broast, Boil, Clear, and Start, but in part-time job she has a "back" button. Also, for no apparent reason, she has # and * buttons, making her number-pad look like a telephone's (with the # and * buttons reversed).