Filipino mocha cake is light and airy with a coffee-flavored batter and is commonly served for breakfast or dessert. The sweet cake is often served without icing. However, if you decide to frost the cake, use a coffee- or vanilla-flavored icing to best accent its flavors. Approximately one hour is required to bake Filipino mocha cake, not including cooling time. This recipe yields two 8-inch round cakes or about 18 servings.
Preheat the oven to 350 degrees Fahrenheit.
Combine the all-purpose flour, fine salt, baking powder, instant coffee granules and 1 cup of the sugar in a medium mixing bowl. Stir to blend the dry ingredients evenly and make a well in the center.
Pour the hot water and the vegetable oil into the well and blend it into the dry ingredients with an electric beater set to medium. Once the batter is smooth, add the egg yolks one at a time and beat the batter for 5 seconds between each one. Set the batter aside.
Combine the egg whites and the cream of tartar in a clean medium mixing bowl. Attach a whisk onto the electric beater and blend the egg white mixture at high speed for 5 minutes. Add the remaining sugar 1 tbsp. at a time, beating for 3 minutes in between.
Pour the egg white mixture into the cake batter and gently fold the two mixtures together until just blended.
Pour equal amounts of the batter into each greased and floured cake pan. Place the cake pans into the oven and allow them to bake for 15 minutes or until a toothpick poked into the center comes out clean.
Remove the cake pans from the oven and allow them to cool for 1 hour. Top with a coffee- or vanilla-based icing, if you prefer, and refrigerate them for 1 hour before serving the Filipino mocha cakes.