Preheat the oven to 325 F. Grease and flour a 9x9 inch metal square or round 9 inch pan. If you want an easy release, grease the pan then line it with parchment paper.

*Your eggs should be at room temperature for this cake, if they aren’t set them in a bowl of hot water to warm.

In a large bowl, melt the butter. Add in the sugar, salt and vanilla and whisk vigorously for about 60 seconds.

Add the eggs, one by one, whisking for at least 30 seconds between each addition.

Sift in the cocoa and whisk to combine.

Sift in the cake flour and add the baking powder to the mix. Begin whisking then add the sour cream and boiling hot water. Whisk until the batter is smooth, scraping at the sides of the bowl to ensure all the batter is well mixed.

Pour into the prepared cake pan. Bake the cake until the top springs back when pressed or a cake tester comes out clean; about 30-35 minutes.

Let the cake cool briefly in the pan then transfer to a wire rack to fully cool.

To make the whipped cream: set all the ingredients in a food processor and process on high until thickened. Because of the black cocoa this won’t thicken like whipped cream usually does, it will have more runnyness to it but it will set once spread on the cooled cake.