Exceptional Expanding Gases, aka Awesome Amaretti Cake

Hello fellow internet cooks/scientists, sorry it's been so long since I've posted anything. Things have been crazy here, because... I've moved to new digs in Minneapolis. In fact today is the first time in a few weeks that I have had groceries and used an oven. And how did I start? I made an Italian birthday cake. Appropriate since my birthday is this week.

European cakes, especially Italian cakes, don't use chemical leavening agents (baking soda, baking powder, etc.) to create expanding gases. Instead they use the gases that is already there to raise their cakes. How this works is that egg whites are whipped. As the get stirred up the proteins get further and further apart creating little pockets of trapped atmospheric gases. Eventually the mixture becomes a stiffened protein network with air pockets. Something that we call a meringue. This is then carefully folded (so that the air isn't released) into a cake batter and baked. Most gases follow the ideal gas law (see Preservation Part II). So, because the gases, for the most part can't escape, as the temperature goes up the pressure increases, pushing on the liquidy cake batter harder and harder, until it expands. This creates more volume for the gases to occupy, and the cake to rise.

This cake, like most European cakes is rich and dense, and served without frosting (as a side note my cake was denser than most, I only used 2 eggs, I don't know why so don't ask). The cookies are key because they give it a characteristic sweet almond flavor. I got my tin of cookies online, but you can also find them in Italian groceries and some specialty stores. I highly recommend serving it with whipped cream, vanilla ice cream, or cherries. You can find the original recipe here: http://www.ciaoitalia.com/Recipes.aspx?id=1072

Torta di Amaretti e Cioccolato

Ingredients

2 sticks butter

1 cup sugar

5 eggs

10 pairs amaretti cookies

1/2 cup flour

2 oz semi-sweet chocolate, coarsely chopped

Preheat the oven to 350 degrees. Grease and flour the sides and bottom of a 9 inch spring form pan. Cream the butter and sugar together with an electric mixture. Separate the eggs and beat the yolks one at a time into the batter. Save the whites. Process the cookies and flour in a blender until powdery. Add the pieces of chocolate and process until finely chopped and mix in to the batter. Beat the egg whites until stiff peaks form. Stir 3-4 Tablespoons of the egg whites into the cake batter to loosen the batter up. Then carefully fold in the remaining egg whites. Pour into the prepared pan and smooth until even. Bake until a toothpick inserted in the center comes out dry (~1 hour)*. Remove the cake from the pan and enjoy.

*be sure to put a baking sheet under the pan to keep the drippings from smoking up your kitchen (like I did mine).