Brocho before eating this:
One should say the Brocho on the ingredient he primarily desires. (in other words Borei Pri Ha'eitz if he desires the Almond, or Shehakol Niyeh Bedvoro if he desires the chocolate).
If one has no clear preference: there is a difference of opinion, so it is preferable to say Borei Pri Ha'eitz.
Brocho after eating the proper shiur of this: Borei Nefashos
Source: The Laws of B'rachos (pages 215, 359)
Also see: Almonds