Preheat your oven to 180°C (350°F) to create the perfect environment for baking your Ube Leche Flan Cake.

In a medium-sized pot, add 200g of granulated sugar and heat it over medium heat, stirring constantly until it turns a rich amber color. Pour the caramel into the cake tin and let it set.

In a mixing bowl, combine 6 egg yolks, 320g of condensed milk, 350ml of evaporated milk, 2 teaspoons of vanilla extract, and 1/8 teaspoon of salt. Whisk until smooth, then strain it through a fine mesh sieve into the cake tin over the caramel.

In a clean bowl, add 3 egg whites and 1/4 teaspoon of cream of tartar. Whip the egg whites until foamy, gradually add 60g of sugar, and whip until stiff peaks form.

In another bowl, whisk together 3 egg yolks with 60g of sugar until light and creamy. Mix in 40ml of vegetable oil, 50ml of cold water, and 1 tablespoon of ube extract, then sift in 100g of plain flour, 1/2 teaspoon of baking powder, and 1/8 teaspoon of salt.

Gently fold half of the whipped egg whites into the ube cake batter. Add the remaining egg whites and fold until smooth.

Place the cake tin in a roasting tray. Pour boiling water into the tray until it reaches halfway up the sides of the cake tin.

Transfer the roasting tray to the oven and bake for 55-60 minutes until a toothpick inserted comes out clean and the flan is set.

Let the cake cool in the water bath for about 30 minutes. Then refrigerate for at least 4 hours, ideally overnight.

Run a knife around the edge of the tin to loosen. Invert the cake onto a serving plate and enjoy with family and friends.