Especially and specially look similar, but they are not usually interchangeable.
Use especially when you mean particularly, above all, or more than others. It often adds emphasis.
- I love winter, especially December.
- She was especially kind to the new student.
Use specially when you mean for a special purpose, in a special way, or made for someone or something.
- This bag was specially designed for cyclists.
- The chef specially prepared a vegan meal.
A simple memory tip can help: especially highlights what stands out, while specially describes purpose or design.
In everyday English, especially is more common. If you are choosing between the two, ask yourself: am I emphasizing one thing, or talking about a special purpose? That question usually gives you the right word.