9 tbsp (125g) unsalted butter, or one stick plus one tbsp
7 oz (200g) best-quality dark (60-72%) chocolate, roughly chopped or in discs
⅓ c (30g) dark cocoa powder, dutch-process or natural
4 large eggs, separated
1 c (200g) baker's/caster sugar
½ tsp vanilla extract
2 tbsp coffee, espresso, or water, cooled
⅓ c (40g) all-purpose flour
¾ tsp baking powder
⅛ tsp salt
Instructions
Preheat oven to 350 degrees.
Butter an 8 or 9 inch round baking pan and line the bottom with a round of parchment paper. Dust the pan with cocoa powder and tap out the excess.
Melt butter in a large saucepan over low heat. Remove from heat and stir in both the dark chocolate and the cocoa powder until smooth. Set aside to cool.
In a medium bowl, whisk egg yolks, sugar, vanilla and coffee or water until lighter in color and smooth. Stir into chocolate mixture until combined.
Sift flour and baking powder together, then add to chocolate mixture and stir until just combined.
With a paper towel and a little lemon juice or vinegar, wipe a whisk and stainless bowl clean to remove any trace of grease. Whisk egg whites and salt by hand or with a mixer just until soft peaks form. Gently fold into chocolate mixture until incorporated and no white streaks remain. Pour into prepared pan.
Bake for 20 minutes, and rotate the cake. Bake for 5-10 minutes more, checking every couple minutes until a toothpick or skewer inserted in the center comes out with moist crumbs. Be careful not to over bake.
Place pan on a cooling rack for 10 minutes, carefully run a sharp knife around the edge of the cake to loosen it from the pan, and turn over onto your hand, then back onto the cooling rack until cool. I found it was easier to turn the cooled cake on the rack onto my hand then onto a plate instead of trying to pick it up, the cake is very delicate.
Give a thorough dusting with powdered sugar. Can be served warm or cool (will be more dense), alone or with fresh whipped cream or ice cream, raspberries, strawberries, you get the idea. And you're welcome.
Recipe by oh honey bakes at https://ohhoneybakes.com/a-deliciously-simple-chocolate-cake/