2large eggsset them in a bowl of warm water as soon as you begin baking, this will bring them to room temp
150g or 1cupplus 2 tablespoons cake flour
50g or ½ cupnatural cocoa powder
½teaspoonbaking soda
190g or ¾cupskefir or buttermilkat room temperature
60g or ¼cupboiling hot water
Instructions
Preheat the oven to 350 F and grease and line an 8x8” square cake pan with parchment paper crosswize (to make a +, this makes for easy lifting).
In the bowl of a stand mixer or using a hand mixer, beat together the butter and sugar as well as the vanilla and salt. Beat for a good 5-6 minutes, until it’s very light and fluffy.
Add the eggs one at a time, beating well between each addition (at least a minute).
Over the batter, sift the cocoa, baking soda and cake flour. With the mixer on, begin beating and pouring in the kefir slowly. Add the hot water. Beat until batter is just combined.
Pour into prepared cake pan and bake for about 30 minutes, until you can touch the center of the cake and it springs back (or use a cake tester).
Cake should be completely cool before spreading the buttercream on top.