What Bracha do you make on a Buckwheat Muffins?

The Bracha Rishona on Buckwheat Muffins is as follows, Mezonos or Shehakol, and the Bracha Acharona is as follows, Al Hamichya or Borei Nefashos.

If the buckwheat muffins contain flour of the Chameshes Minei Dagan (five species of grain) and a K'zayis of Chameshes Minei Dagan flour is eaten within a Kdei Achillas Pras (2-9 minutes), one recites an Al Hamichya. Otherwise one says Borei Nefashos. However if the muffins do not contain flour of the Chameshes Minei Dagan, a Shehakol is said because the buckwheat no longer has its original form.