Mince pies contain mincemeat, and you probably wouldn’t want to put brandy cream on a pie containing minced meat.
Minced meat: Meat that has been cut up into very small pieces (usually by a machine).
Mincemeat: A mixture of dried fruit, sugar and spices. It may also contain alcohol (often brandy) and suet.
Mincemeat did once contain actual meat, and there is an interesting article on the history of the filling of mince pies here. Some dictionaries do give mincemeat as another word for minced meat, so be sure to check the context it is being used in.