The words especially and specially have just a hair's breadth of difference between them. Both can be used to mean "particularly." Especially tends to be more formal, while specially tends to be more informal:

Barney Frank can be ruthless in debate, especially when laying into opponents who try to evade the historical record.

This season, Essie Cosmetics is commemorating 2010 Breast Cancer Awareness month with specially created We Can Do It Pink!

But our words have finer points to them that are worthy of being understood. Especially carries with it a sense of something exceptional, implying that there is something else that is of lesser quality:

We came to win the game and I thought we played especially well in the first half.

Charlotte Daw Paulsen, a mezzo-soprano, as Jephtha's wife, was especially fine in her harrowing "Scenes of horror, scenes of woe."

Specially can refer to something with a distinct purpose, someone who stands apart from the rest, without insinuating that there is something or someone who is lesser:

Specially trained dogs may be useful in helping to calm autistic children.

Value Village's specially trained costume consultants will showcase the hottest costumes.

Now that you know the finer points, you can choose your words — especially especially and specially — carefully.