Preheat oven to 350°F/175°C. Grease a donut pan with butter or baking spray.
Whisk together the flour, brown sugar, cocoa powder, nutmeg, baking powder, baking soda, and salt in a large bowl. Combine buttermilk, egg, melted butter and vanilla extract.
125 grams all purpose flour, 25 grams cocoa powder, ½ teaspoon baking powder, ½ teaspoon baking soda, ½ teaspoon kosher salt, 56 grams unsalted butter, 106 grams light brown sugar, 113 ml buttermilk, 1 egg, ¼ teaspoon nutmeg, 1 teaspoon vanilla extract
Pour buttermilk mixture into dry mixture and fold in until all incorporated. Make sure there are no flour pockets.
Pipe the batter into the cavities, filling each ¾ of the way. Bake for 11-13 minutes, until golden brown and springy to the touch. After 5 minutes take out each donut and let cool on a wire rack, before pouring the next batch in. I like the re-grease the pan before I refill it.
Vanilla Glaze
Combine all ingredients together in a medium bowl until completely smooth. Dip each cooled doughnut in and let dry on a cooling rack above a paper towel.
My recipes have been developed and tested in metric grams. I highly recommend using a weighing scale and measuring out your ingredients the metric way. I have provided a conversion to US cups but please note that I haven’t tested the recipe with this method.Nutmeg: I've had a few comments about adding nutmeg, feel free to leave it out or add just ⅛ teaspoon if you aren't a huge nutmeg fan! Salt: If you don’t have kosher salt, halve the amount of salt called for in the recipe. 1 teaspoon kosher salt = ½ teaspoon fine salt.Buttermilk: No buttermilk on hand? You can substitute it for sour cream.Storage: Keep the donuts in an airtight container and keep in the fridge for up to 3 days. You can freeze the donuts for up to 3 months, let them defrost overnight in the fridge before eating.