6 Tbs. (3/4 stick) unsalted butter, at room temperature
½ cup granulated sugar
1 egg
For the cinnamon-sugar mixture (optional):
½ cup granulated sugar
1½ tsp. ground cinnamon
For the glaze (optional):
1 cup confectioners’ sugar
1½ Tbs. whole milk
Directions
To make the donuts, preheat oven to 350°F. Grease the wells of a mini donut pan.
In a large bowl, whisk together the flour, baking powder, baking soda, salt and nutmeg. In a measuring cup, stir together the buttermilk and whole milk. Set aside.
In the bowl of an electric mixer fitted with the flat beater, beat together the butter and granulated sugar on medium speed until light and fluffy, about 2 minutes. Stop the mixer and scrape down the sides of the bowl. Add the egg and beat on medium speed until combined, about 1 minute.
Reduce the speed to low and add the flour mixture in three additions, alternating with the buttermilk mixture and beginning and ending with the flour. Beat each addition until just blended.
Pour a scant 1 Tbs. batter into each prepared well. Bake until a toothpick inserted into the donuts comes out clean, about 8 minutes, rotating the pan halfway through baking. Transfer the pan to a wire rack and let cool for 5 minutes, then invert the pan onto the rack and lift off the pan.
Wash and dry the pan and repeat with the remaining batter.
If making the cinnamon-sugar mixture, place the granulated sugar and cinnamon in a small bowl and whisk until combined. While the donuts are still warm, toss them in the mixture and transfer to a wire rack.
If making the glaze, place the confectioners’ sugar and milk in a small bowl and whisk until combined. Let the donuts cool completely, then dip them, top side down, into the glaze. Transfer the donuts, glazed size up, to a parchment-lined baking sheet. Makes 24 donuts.