01 -
Get your oven going at 170ºC/340ºF (regular mode) and grab three 20 cm (about 8 inch) baking pans lined with parchment. Brew your coffee and weigh it so it can chill out while you get the rest together.
02 -
Toss all your dry stuff like sugar, flour, cocoa powder, cornstarch, salt, baking powder, and baking soda into one bowl. Sift 'em and give everything a good mix to keep it even.
03 -
Grab another bowl and throw in your wet stuff—oil, sour cream, eggs, coffee, and vanilla. Gently whisk together by hand just until it looks smooth. Don’t go crazy with the whisk or your eggs might get too bubbly.
04 -
Add your wet mix into the dry bowl slowly, turning the batter gently until you can't find any lumps. Pour the mix into your lined pans and pop ‘em in the oven for 28-30 minutes. If a toothpick comes out clean, you're golden.
05 -
Put the cakes on a rack right out of the oven. After about five minutes, tip them out of the pans and let them really cool down all the way.
06 -
Mix the coffee and instant espresso (if you want) in a small mug or bowl. This kicks up the flavor. Sift your powdered sugar now too and leave it ready to go.
07 -
Beat the butter with a stand mixer or hand mixer for four minutes on medium-high. Scrape down the bowl, then keep mixing two more minutes. Add half the powdered sugar, vanilla, and coffee, beat till smooth, then do the rest. Once it’s all mixed, scrape down once more and give it a final two-minute whip.
08 -
Even out the tops of your cake layers if needed. Throw the first layer on your turntable or serving plate and pile on three generous scoops of frosting, smoothing it out with your offset spatula. Stack the second cake, do it again, and then the last. Smear the whole thing with a thin layer to catch crumbs, then finish with the rest of your frosting all over.