Why in the long method for the Old Fashioned Chocolate Cake, do you add the cocoa powder to the wet ingredients rather than the dry like you would normally? Does it make a difference to the end result?
It is easiest to make Nigella's Old Fashioned Chocolate Cake (from FEAST) in a food processor as you can just blitz all of the ingredients together. However if you make the cake in a mixer then the flour, sugar and levening agents are mixed with the butter first and the other ingredients are added after. With this method the butterfat coats the glutens in the flour and helps reduce the amount of liquid that mixes with the glutens, leading to a more tender cake.
Cocoa powder tends to be slightly lumpy so it is easier overall to dissolve it in the sour cream and egg mixture first and then add this to the flour mixture. Otherwise, you would need to start by sifting together the flour, cocoa and leavening agents before adding the sugar and butter and continuing with the recipe.