- Bake the cakes. Heat the oven to 350 degrees. Line a muffin pan that makes 6 large muffins with muffin papers.
Place the flour, 6 tablespoons of the sugar, the baking powder and a pinch of salt in a large bowl and whisk to combine. Separate the eggs, dropping the whites into the bowl of a mixer and the yolks into a medium bowl. Add the oil, vanilla and 2 tablespoons of water to the yolks and mix well. Beat the egg whites with the cream of tartar until they start to thicken and form soft peaks. Gradually add the remaining 6 tablespoons of sugar and continue to beat until stiff peaks form.
Add 1/3 of the flour mixture to the egg yolks and mix well. Gently fold in 1/3 of the beaten egg whites. Repeat, alternating the flour mixture and egg whites until everything is thoroughly combined. Scoop the fluffy batter into the prepared muffin tins, place in the hot oven and bake until the tops spring back when touched, 20 to 22 minutes. Allow to cool slightly, then take the individual cakes out of the molds, remove the papers and invert them into a deep 13x9 inch baking dish.
- Make the three milks mixture. Combine the heavy cream, evaporated milk, condensed milk, coffee, vanilla, cinnamon and a pinch of salt in a bowl and mix well. Slowly pour the mixture over the cakes, soaking them thoroughly. Cover with plastic wrap and refrigerate for 1 hour to allow the milks to be absorbed into the cakes.
- Frost the cakes with meringue and serve. Combine the sugar with 1/3 cup water in a small (2-quart) saucepan and bring to a boil over high heat, swirling the pan gently until all the sugar is dissolved. Dip a brush in water and use it to clean the sides of the pan so no sugar crystals remain. (This is an important step in keeping the syrup from recrystallizing.) Lower the heat to medium and boil the syrup until it reaches soft ball stage (when a little syrup dropped into cold water will form a soft ball).
While the syrup is boiling, beat the egg whites with the cream of tartar and a pinch of salt until the whites form soft peaks. Drizzle in the hot sugar syrup in 4 additions, beating well after each addition. Continue to beat until the bottom of the bowl is cool.
To serve, place each soaked cake on a plate, decorate with a big dollop of meringue, toasting the peaks with a kitchen torch. Sprinkle with the Mexican chocolate and present to your guests to enjoy.