French Chocolate Cake

I've made this cake many times now and really love it; it's quite rich and dense, definitely for chocolate lovers :)  The recipe is another one from the book French: Delicious Classic Cuisine Made Easy by Clements & Wolf-Cohen (yes, I really love this cookbook a lot).  The first few times I made this, I could not find superfine sugar where I lived, so I used regular/granulated sugar instead; it still turned out, but not exactly the same texture (still delicious!)

My YouTube video of preparation: https://youtu.be/a6wAHp5E570

Ingredients:

3/4 c. superfine sugar, separated, plus some for sprinkling
10 oz. semisweet chocolate chips
3/4 c. unsalted butter, cut in pieces
2 tsp. vanilla extract
5 eggs, separated
1/4 c. all-purpose flour, sifted
pinch of salt
confectioner's sugar, for dusting (if desired)

Instructions:

1. Heat oven to 325°F.  Butter a 9 1/2" springform pan, then sprinkle with superfine sugar to coat, tap out excess.

2. Set aside 3 T. of the superfine sugar (taken from the 3/4 c.).  Place the chocolate, butter, and remaining sugar in a medium heavy saucepan.  Cook over LOW heat until the chocolate and butter have melted and sugar has dissolved.

3. Remove pan from heat and stir in the vanilla extract.  Let mixture cool slightly.

4. Beat the egg yolks into the chocolate mixture (I just stirred vigorously), then stir in the flour. (I put this in bold due to my oops while making the video!)

5. In a clean, grease-free bowl, using an electric mixer, beat the egg whites until they are frothy.  Add the salt, increase the speed, and continue beating until soft peaks form.

6. Sprinkle the remaining superfine sugar over the top of the egg whites and beat until the whites are stiff and glossy.

7. Add 1/3 of the whites the to chocolate mixture and beat in carefully.  Fold in remaining 2/3 of whites (by hand).

8. Carefully pour mixture into the prepared springform pan and tap the pan to release any air bubbles.

9. Bake the cake for 35-45 minutes (I went 36), until well-risen and top springs back when lightly touched.

10. Transfer cake to cooling rack and run a knife around the edge of the pan to loosen any bits that may have stuck to the pan.  Remove the side of pan and let cool completely.  Note: the top of the cake will be crackly and the cake will deflate a bit while cooling.

11. The original recipe calls for removing the cake base at this point; I find that the cake is too fragile for this operation, so I just leave it on the base for serving.  Dust top of cake with confectioner's sugar if desired (I don't find this necessary, I like it as it is :))  Slice up and enjoy!