when mixing the cake batter for ROSE’S heavenly CAKES: Chocolate Ice Cream Sandwich (page 142), i made a 2x recipe and must disclose that i added the oil and yolks to the mixer bowl prior adding the cocoa and water mixture. it is my suspicion, when your mixer bowl is first coated with oil, then nothing will stick to it, making scraping completely unnecessary. cocoa has a reputation to stick to everything!
this was an accidental method. i had the cocoa and water mixture made several days ahead from a mistake cake. and since i am using frozen eggs, i decided to thaw the eggs on the mixer bowl at room temp straight from frozen. adding the oil on the eggs also prevents the thawing eggs from drying.
let these pictures be the proof. when i was scraping the bowl, there really was nothing to scrape after!