2 ½cupscake flourplus extra for dusting pans (280 grams)
1 ¼teaspoonsbaking powder
¼teaspoonbaking soda
¾teaspoonsalt
1 ¾cupssugar (divided use, so watch out!)(350 grams)
10tablespoonsunsalted butter , melted and cooled slightly(140 grams)
1cupbuttermilk, room temperature(230 grams/ml)
3tablespoonsvegetable oil
2teaspoonsvanilla extract
6largeegg yolksroom temperature
3largeegg whitesroom temperature
Milk Chocolate Frosting
8ounceschopped milk chocolate (dark okay too)
2 ½sticksunsalted butter, cool and cut into small chunks(280 grams)
1cuppowdered sugar(120 grams)
¾cupunsweetened cocoa powder (Dutch or natural)
⅛teaspoonsalt
¾ cuplight corn syrup
1teaspoonvanilla extract
Instructions
Preheat oven to 350 degrees. Grease two 9-inch-wide by 2-inch-high round cake pans and line bottoms with parchment paper. Dust with flour.
Whisk flour, baking powder, baking soda, salt, and only 1 ½ cups sugar together in large mixing bowl or in the bowl of a stand mixer. bowl. Reserve the remaining ¼ cup of sugar for the whites.
Whisk melted butter, buttermilk, oil, vanilla, and yolks in another bowl (or a 4 cup liquid measure).
Begin beating dry ingredients at low speed with the mixer. Gradually pour in butter/yolk/oil mixture and mix until almost incorporated (a few streaks of dry flour will remain), about 15 seconds. Stop mixer and scrape whisk and sides of bowl. Return mixer to medium-low speed and beat until smooth and fully incorporated, 10 to 15 seconds.
Beat egg whites until foamy. Gradually add remaining ¼ cup sugar and beat until stiff peaks just barely start to form -- they don't need to be dry.
Using rubber scraper, stir ⅓ of whites into batter to lighten, then add remaining whites and gently fold into batter until no white streaks remain. Divide batter evenly between prepared cake pans. Lightly tap pans against counter 2 or 3 times to dislodge any large air bubbles.
Bake for 20 to 22 minutes (up to 27) or until cakes appear set and are beginning to pull away from sides of pan. Let cakes cool on wire rack for 10 minutes. Loosen cakes and invert.
Milk Chocolate Frosting
Melt the milk chocolate in the microwave using 50% power and stirring every 30 seconds to 1 minute. Let it cool.
In the bowl of a food processor, process butter, sugar, cocoa powder and salt until smooth. Add corn syrup and vanilla and pulse until smooth, then scrape sides of the bowl and add chocolate. Process until smooth and creamy. Ice the cake immediately.