Preheat the oven to 325°F (163°C). Do not grease the chiffon pan to allow the batter to cling to the sides.

Whisk together the egg yolks, ½ cup of granulated sugar, milk, vegetable oil, vanilla extract, cooled mashed taro, and ube halaya until smooth.

In a separate bowl, whip the egg whites and a pinch of salt until foamy. Gradually add the cream of tartar and remaining sugar until stiff peaks form.

Gently fold one-third of the meringue into the yolk mixture, then carefully add the remaining meringue until no streaks remain.

Pour the batter into the ungreased chiffon pan and bake for 30–35 minutes until golden and springs back when touched.

Once baked, immediately invert the pan to cool completely for about an hour.

Whip the heavy cream until soft peaks form and fold in the ube halaya.

Remove the cooled cake from the pan, spread the whipped topping over the top, slice, and serve.