1lbchocolatenote that your final cake will taste exactly like the chocolate that you use. I used an entire pound of Hershey bars, and I adored the final product. Some of the other Daring Bakers used mostly bitter dark chocolate, and they were less pleased with their final product.
1/2cup plus 2 tablespoonsbutterunsalted
Melt chocolate and butter in a double boiler, stirring often. (I am going to try to pre-melt the butter next time since it took a lot longer than the chocolate to melt and become smooth.)
While the chocolate and butter mixture is cooling, butter an 9" springform pan; line with a parchment circle, then butter the parchment. This is an important step!
Separate the egg yolks from the egg whites and put into two medium bowls.
Whip the egg whites in a large grease free bowl until stiff peaks are formed (do not over-whip or the cake will be dry). If you try to do this by hand, your arms will be so tired that you'll think they are falling off and the egg whites will not become stiff enough. Learn from my mistake, and use some kind of electric mixer. A hand mixer would probably be best, but I'm going to try my stand mixer next time because I don't have a hand mixer.
With the same beater, beat the egg yolks together. Add the egg yolks to the cooled chocolate.
Fold one-third of the egg whites into the chocolate mixture and follow with the remaining two-thirds. Carefully fold until no white remains without deflating the batter.
Pour batter into the prepared pan. The batter should fill the pan ¾ of the way.
Bake at 375F for about 25 minutes.
The top of the cake will look similar to a brownie and a cake tester will appear WET.