Tres Leches Cake

The best tres leches cake I've ever eaten was from a little Mexican restaurant that I found in Baltimore. That place made the most amazing sopes and pambazos but I thought that the tres leches cake was the star. The thing that made it so good was the hint of cinnamon. And let me be clear, the cinnamon was incredibly subtle; the cake smelled sweet and autumnal but didn't necessarily taste that way.

I thought for a while (I guess it was a thought I came back to over the course of three years, considering I ate that infamous tres leches back in 2012) trying to figure out how I could achieve the same subtle cinnamon flavor. Then it occurred to me: flavor the soaking liquid with a cinnamon stick!
Ingredients [yields 8" x 8" pan]:
3 eggs, separated
½ cup + ½ cup sugar
1 teaspoon vanilla extract
½ teaspoon salt
1 cup flour
¼ cup milk
pinch cream of tartar
1½ cup light cream
½ cinnamon stick
5 oz. evaporated milk
14 oz. sweetened condensed milk
1½ cups heavy cream
1 tablespoon powdered sugar

The cake batter contains zero chemical leavening agents. Instead, it's all mechanical leavening, i.e. incorporating lots of air into the batter. So, start by separating the eggs.
Set the whites aside because we're going to work with the yolks first. To the bowl, add salt, sugar, and vanilla extract and whip the heck out of it until they go from yellow to a pale beige. The pallor is indicative of the amount of air whipped into the batter.
To the yolk mixture, add half of the flour mixture and carefully fold. Then, pour in the milk and carefully stir. Then, pour in the rest of the flour and carefully fold again and then set this half of the batter aside. It's important that the batter is not overmixed; overmixing will deflate too much of the air.
Next, divert your attention to the whites. Start by beating the whites until they're frothy and then add in a pinch of cream of tartar. Cream of tartar is an acid, which stabilizes the egg whites, i.e. it's a "safety" measure which prevents the whites from collapsing. Once the egg whites are at soft peaks, drizzle in the sugar and whip furiously until the meringue is firm and at stiff peak stage.
Now it's time to join the whites and the yolks.
Carefully, v. carefully, fold the egg whites into the yolks. Fold just until combined and if there are a few minor streaks, ignore them. Again, this is to preserve the air bubbles that were so painstakingly incorporated into each component of the batter.
Pour the batter into a greased pan and use a spatula to spread it into an even layer and tuck the batter into the corners.
Bake at 350F for 30 minutes or until golden brown and a toothpick inserted in the center comes out clean.
Leave the cake to cool.
While the cake is cooling, get working on the soaking liquid portion of the tres leches cake. Pour the heavy cream into a saucepan along with a cinnamon stick. Heat until scalding.
Remove the cream from the stove and stir in the evaporated milk and the condensed milk.
Prepare the cake for soaking by grabbing a skewer and poking holes all over. Then, pour the milky mixture all over the top, nice and slowly. Watch as the spongey cake soaks it all up.
At first it may look like the cake won't soak up all of the liquid but all of a sudden, it will disappear.
Make a batch of whipped cream by whipping heavy cream with some confectioner's sugar and then frost the cake with it.
At this point, the cake can be served right away but I prefer cold tres leches cake so I like to pop it in the chiller for 2 hours before digging in.
The cake is super tender with a soft crumb and it's incredibly sweet and creamy, thanks to the soaking liquid. The fluffy, lightly sweetened whipped cream is a refreshing topping. This cake is so good and I totally nailed the subtle cinnamon flavor. Yay, me!
Here's the recipe page: