1. Preheat the oven to 350°F (175°C) if you are baking the donuts.
2. In a large mixing bowl, whisk together the dry ingredients: all-purpose flour, cocoa powder, baking powder, baking soda, salt, and nutmeg.
3. In a separate bowl, mix the wet ingredients: melted butter, light brown sugar, buttermilk, eggs, and vanilla extract until smooth.
4. Gradually combine the dry ingredients with the wet mixture, folding until a smooth batter forms.
5. Grease the donut pan and pipe the batter evenly into the molds.
6. Bake the donuts in the oven for 11-13 minutes or until a toothpick inserted comes out clean.
7. Allow the baked donuts to cool slightly before glazing.
8. To prepare fried donuts, start by creaming the butter and sugar together using a stand mixer or bowl.
9. Add egg yolks to the butter-sugar mixture and mix until well incorporated.
10. Gradually blend in the dry flour mixture to create a dough, ensuring no clumps remain.
11. Chill the dough in the refrigerator for at least 30 minutes or overnight.
12. Roll out the chilled dough and cut into donut shapes using a cutter.
13. Heat oil in a deep fryer or large pot and carefully fry the donut shapes until golden brown on both sides.
14. Drain the fried donuts on a wire rack to remove excess oil and let them cool slightly before glazing.
15. For the glaze, mix confectioners’ sugar, milk, vanilla extract, and a pinch of salt in a bowl until a smooth consistency forms.
16. Dip each cooled donut into the glaze, ensuring an even coating on all sides.
17. Place the glazed donuts on a wire rack and allow the glaze to set slightly before serving.