Make Ube Flan Cake the easier way– whole eggs for the flan and a handy boxed cake mix! In this Filipino dessert, both the flan and cake take the spotlight, with the sweet, nutty ube wonderfully complimenting the creamy leche flan.Recipe note: Ube halaya is optional. If included, the chiffon cake will have a slightly richer texture.
Caramel - Place all the ingredients of the caramel in a small pot and stir. Bring to a simmer over medium heat. Swirl every so often until it liquefies and the color turns into a color amber. Remove from heat when it turns golden. Residual heat will keep cooking the caramel.
While the caramel is still hot, pour it into the baking pan. Quickly swirl to coat the bottom and sides of the pan evenly. Use thick oven gloves to hold the pan. Let it cool to set.
Flan - Gently whisk the eggs in a large bowl. Add condensed milk, evaporated milk, vanilla, and salt. Stir everything together until combined. With a fine mesh strainer, strain the flan into another bowl. Set aside.
Cake
Separate egg yolks from egg whites. Place them in separate bowls. I recommend using a large stainless bowl for the egg whites.
Cake batter - In the bowl of egg yolks, add ube halaya, butter, and ube extract. Stir to combine. Sift the cake mix into the wet mixture using a fine mesh colander. Stir until just combined. If you prefer a deeper ube color, add a drop of violet or purple gel color or 1/4 tsp liquid food color. Add more based on preference.
Egg white - Add lemon juice to the bowl of egg whites. Beat on high speed until firm peaks form. It's ready when the meringue stands tall and does not fall back into itself.
Pour 1/3 of the egg white mixture into the cake batter and whisk until thoroughly combined. Add the mixture to the remaining whipped egg whites. GENTLY FOLD this time using a spatula (don't stir). Do not over-mix the batter or it will deflate.
Assemble
Have the hot water on standby for the water bath. Don't pour it yet.
Place the pan(s) with the caramel into a larger roasting pan. I use the pan that came with my oven.
Flan layer - pour the flan mixture into the pan. If using two small pans, divide it as equally as possible.
Cake layer - pour the ube cake mixture over the flan mixture. Again if using two pans, divide it as evenly as you can. Using a spatula, smooth the surface as evenly as possible.
Water bath - Carefully pour hot water into the larger roasting pan, about halfway up the side of the round pan.
Bake and cool
Bake the cake in a preheated oven until a toothpick inserted into the center comes out clean. Cooking time is approximately 45 minutes for a 7-inch pan and 60 to 65 minutes for a 9-inch pan. Do not overcook. You can start checking the doneness at about 60 mins.
Remove from the oven. Transfer the pans to a cooling rack. Don't remove the cake yet. Let it cool completely then cover the pans with plastic wrap and refrigerate overnight (note 4).
Serve
Loosen the sides of the flan cake using a thin spatula then invert onto a wide-rimmed serving plate. Slice, serve, and enjoy!
Notes
Pan size - I recommend using round-sized baking pans for easy serving. If using 2 smaller cake pans use 1/2 cup sugar with 2 tbsp water; for one 9-inch pan use 1/4 cup sugar with 1 1/2 tbsp water
Ube halaya - use homemade ube halaya or jarred ube jam. This recipe has not been tested with ube powder.
Vanilla Cake mix - you can also use yellow cake mix. Use the 15.25 OZ box and not the 13.25 OZ.
Chill in the refrigerator overnight to let the caramel transform into syrup; patience is key here.