First, separate the ingredients into two sets:
One set is the dry set: Flour, Nutmeg, Baking Powder, and Salt.
The other set is the wet set: Eggs, Butter, Sugar, and Sour Cream. Yes, sugar is a dry item, but it's going in with the wet stuff later :)
Mix the dry set - Flour, Nutmeg, Baking Powder, and Salt - in a large bowl. Use a whisk to mix these together; this also fluffs the flour up a bit and breaks up clumps.
Melt butter, and let it cool slightly. Hot butter will cook the eggs, and we don't want that. So let it cool.
Mix the wet ingredients - Eggs, Butter, Sugar - in a bowl. Mix this well but do not whip. It will be semi-sandy in texture, and it will turn a lighter yellow color.
Mix the wet and dry ingredients together, and "knead" the dough for 6-8 minutes, until it becomes smooth and all the ingredients are well-integrated. This is a sticky dough, so keep it well-floured as you are kneading it.
Cover the dough and refrigerate for 1 hour.
Roll the dough out into a flat circle, 1/2 inch thick.
Use a cookie cutter to cut the doughnuts and holes. Knead the excess dough back together, re-flatten, and cut more doughnuts.
Fry the doughnuts and holes in 2 inches of Canola oil at 325° F. Cook for 20 seconds, then flip. The dough will be fragile, so flip it carefully.
Cook for another 1 minute, or until the bottom becomes golden brown. What is now the top of the doughnut should be cracked.
Then flip it one more time and cook for another 30 seconds.
Remove from oil and set on cooling rack.
For drying and cooling, I set a layer of paper towels on a cookie rack and the doughnuts on top.
While the doughnuts are cooling, mix up the glaze ingredients.
When the doughnuts are cool, they are ready for glazing. Dip the doughnuts into the glaze, and let the excess run off.
Place them on a cookie rack to let them dry (no paper towels on the rack this time).
Detail with sprinkles, cinnamon, nutmeg, whatever fun things you can think of. I like colorful sugar sprinkles for my topping. The crunch adds some extra texture. As for the color, well, the world could always use a little more color :)