Preheat the oven to 400 F (200 C) and line 12 muffin cups with paper liners.

In a bowl, mix the first 8 dry ingredients and set aside.

Cream the butter with the sugars until the mixture is light and fluffy.
Add the eggs one at a time, mixing for 1 minute between each addition.
Reduce the mixer speed and add the pumpkin puree, vanilla, and buttermilk.
Add the dry ingredients, mixing with a spatula just until moistened.
Add the dried raisins and nuts and mix.

Divide the mixture among the muffin cups and sprinkle with pumpkin seeds.
Bake for 25 minutes or until the top is golden and a toothpick inserted into the center comes out clean.
Transfer to a rack and let cool for 5 minutes in the cups, then remove from the cups and let cool completely on the rack.