1tspcoarse Kosher salt(if using table salt, use half the amount)
1cupwhole sour cream
1 ½cupsunsalted butter,softened to room temperature
1 ½tspvanilla extract
Preheat the oven to 350. Spray the bottoms of three 8-inch round cake pans with non-stick spray.
In a bowl, sift together the flour, sugar, cocoa powder, baking powder, baking soda and salt, then whisk until completely combined.
In another large bowl, whisk together the eggs, milk, sour cream, oil and vanilla until smooth. Add the dry ingredients to the wet, and whisk for about 30 seconds until well combined and mostly free of lumps.
Divide the batter between the pans. Tap the pans lightly on the counter a few times to pop any large air bubbles. Bake the cakes on the center rack for about 25-30 minutes, until a toothpick or cake tester comes out clean or with moist crumbs clinging to it, and the tops spring back when gently touched.
Set the pans on a cooling rack, cover loosely with a clean kitchen towel and cool completely before frosting.
In the bowl of your stand mixer fitted with the whisk attachment, beat the butter for one minute until smooth.
With the mixer on low, add the powdered sugar and meringue powder, mixing to combine.
Add the vanilla and the sour cream; whip on medium speed for 4-5 minutes, scraping the bowl occasionally, until very light and fluffy. If the buttercream is too stiff, you can add a little more sour cream or milk, one tablespoon at a time, until you reach the desired consistency.
Stack and fill the cooled cakes with the buttercream, then frost all over with a thin crumb coat of buttercream. Chill in the refrigerator for 30 minutes, then finish frosting the cake with a final layer of buttercream.
The cake should be kept in an airtight container or cake carrier at room temperature for up to three days.
Keyword Chocolate Cake, High Altitude, Vanilla Buttercream