Flourless chocolate earth cake

This year, my baking for Passover was limited.  I mean, baking for Passover is always limited, but I was particularly limited this year given my school work.  I did manage to make a delicious flourless chocolate cake, though!  This recipe was given to my mom by a friend of hers, who recommends the only garnish needs to be a sprinkling of powdered sugar (but that's not kosher for Passover), so I served it with some cut strawberries.

Passover Chocolate Earth Cake

Ingredients:

2 sticks butter (I used unsalted)
1 pound bittersweet chocolate, chopped into small pieces (I used semisweet, since they're interchangable)
9 large eggs, separated
3/4 cup sugar

Directions:

Preheat oven to 350F.
Butter a 9" springform pan

Melt the chocolate and butter together (I did it in a pot on the stove, though the original recipe says you can use the microwave, but to be careful not to burn it).

Whisk yolks and sugar together until light yellow.
Whisk a small amout of the chocolate mixture into the yolk mixture, then add in the rest of the chocolate mixture once it has been tempered.

Beat whites until stiff.
Fold whites into chocolate mixture.

Pour the batter into the prepared springform pan.
Bake 20-25 minutes.

Let cake start for 10 minutes then release the sides of the pan.

If using powdered sugar, sprinkle it on now.

ENJOY!!!! (This part was copied from the original recipe, too).