Recipe

Step 1: Preheat the oven to 375°F. Grease a 9″ round cake pan and dust lightly with cocoa powder, tapping out the excess.

Step 2: Put the 3/4 cup butter and the sugar into a standing mixer bowl and toss together to coat the butter. Attach the paddle and bowl to the mixer and beat the butter and sugar on low speed until a light paste forms, about 5 minutes. Add the eggs, one at a time, mixing well and scraping down the bowl with a rubber spatula between additions.

Step 3: Meanwhile, sift together the all-purpose flour, cake flour, 1/3 cup cocoa powder, baking powder, and baking soda into a bowl; sprinkle the salt evenly over the top.

Step 4: Stir the zest and extracts into the grapefruit juice.

Step 5: On low speed, add the dry ingredients to the butter in 3 additions, beginning and ending with the dry and alternating with the buttermilk and grapefruit juice. Stop the mixer several times and scrape down the bowl. Mix until just combined; add the sesame seeds and mix briefly to distribute them.

Step 6: Transfer the batter to the prepared pan, smooth the top with a spatula, and tap the pan several times on the counter to settle the batter and release any air bubbles. Bake in the centre of the oven for about 40 minutes, until the sides begin to pull away from the pan, the top is firm to the touch, and a cake tester inserted into the centre comes out clean.

Step 7: Cool the cake in the pan for 10 minutes before inverting onto a rack to cool completely.

Makes one 9″ cake

Reprinted with permission from Johnny Iuzzini & Wes Martin’s Sugar Rush (2014 Clarkson Potter).