In a bowl or measuring cup, dissolve yeast in the warm water; let sit 5-10 minutes. In a microwave-safe dish, heat milk to 110-115°F.
In a stand mixer bowl, combine sugar, salt, shortening, mace and nutmeg; whisk together. Add warm milk and stir to combine. Add 1 1/2 cups of flour, yeast-mixture, and eggs. Using paddle attachment, beat 2 minutes on medium speed. Add the remaining flour and beat until smooth, about 1 to 1 1/2 minutes. Scrape down batter from sides of bowl.
Cover. Let rise in warm place until doubled, about 30 minutes. Meanwhile, grease muffin cups.
Beat down raised batter in about 25 strokes. Fill muffin cups half-full. Tap pans on table to settle the batter. Let rise until batter reaches tops of cups, about 20 to 30 minutes.
Preheat oven to 400°F while batter is rising. Bake 10 to 15 minutes or until well browned on sides and tops. Tip puffs in pans until slightly cooled.
Prepare topping: Combine cinnamon and sugar in bowl. Dip tops and sides of puffs quickly in melted butter, then roll in cinnamon-sugar mixture. Serve warm.