For the muffins: Adjust oven rack to lower middle position and heat oven to 375 degrees.
Mix flour, baking powder, baking soda, salt, nutmeg and mace in medium bowl; set aside.
Beat butter and sugar with electric mixer on medium-high speed until light and fluffy, about 2 minutes. Add eggs, one at a time, beating well after each addition. Beat in one-half of dry ingredients. Beat in one-third of yogurt. Beat in remaining dry ingredients in two batches, alternating with yogurt, until incorporated. Add and Beat in vanilla extract.
Spray twelve-cup muffin tin with vegetable cooking spray or coat lightly with butter. Use large ice cream scoop to divide batter evenly among cups. Fill muffin cups to the top and level them off, about 1/3 cup of batter each. Bake until muffins are golden brown, 25 to 30 minutes.
Remove muffins from the tin and transfer to a wire rack set over a baking sheet to cool slightly, about 5 minutes.
For the top coating: Combine 4 tablespoons granulated sugar and 1/2 tablespoon cinnamon in a small bowl; mix well and set aside.
Use a pastry brush to paint the top of each muffin with the melted butter, then sprinkle each muffin with a teaspoon of the cinnamon-sugar. Or simply dip the tops of muffins into the melted butter, then roll in the cinnamon-sugar. Serve warm or at room temperature.