1 ½cups + 2 tbspcake flour or all-purpose flour,spooned and leveled
1 ½tspbaking powder
½tspcoarse Kosher salt(if using table salt, use half the amount)
½cupfull-fat sour cream
1 ½tspvanilla extract
½tspground vanilla or vanilla bean paste
1 ½cupspowdered sugar
¼tspcoarse Kosher salt(if using table salt, use half the amount)
Preheat the oven to 375 F, and grease your doughnut pans with non-stick baking spray.
In a bowl, sift together the flour, sugar, baking powder and salt. Separately, whisk together the egg and sour cream until smooth, then whisk in the milk, melted butter and vanilla. Add the dry ingredients to the wet, and use a spatula to fold everything together just until combined. The batter will be thick.
Scrape the batter into a piping bag and cut off an inch from the pointed end. Pipe the batter into the doughnut pans, filling them no more than 1/2 - 2/3 full.
Bake the doughnuts on the center oven rack for about 10-12 minutes, until a toothpick comes out clean. Cool the doughnuts for several minutes in the pan, then gently remove the doughnuts and let them cool completely on a cooling rack before adding the frosting.
To make the browned butter, melt the butter in a saucepan over medium heat. Continue to cook the butter, swirling the pan occasionally, until the butter starts to foam and nutty brown solids form at the bottom of the pan.
Set the butter aside to cool to a room temperature solid. This could take several hours, but to speed things up, put the bowl in the refrigerator, and stir the butter every 10 minutes, until it's cooled down and started to solidify. You can make the butter a day in advance, if you like, and just let it sit at room temperature until needed.
In the bowl of your stand mixer fitted with the whisk attachment, whip the cooled brown butter with the powdered sugar, meringue powder, salt, vanilla and milk for about 4-5 minutes on medium speed, until very light and fluffy.
Pipe the frosting onto the cooled doughnuts and serve.
Store leftover doughnuts in an airtight container at room temperature for up to 2 days.
Keyword Baked Doughnuts, Brown Butter, Vanilla Cake