Preheat oven to 176°C. Grease the baking pan and line it with parchment paper. Lightly grease the parchment paper.
In a large mixing bowl, whisk the yolks with a hand whisk until lighter in color. Add the sugar and continue to whisk the mixture until it has slightly thickened. Add the milk, canola oil, and ube extract to the bowl. Whisk until incorporated.
In a separate bowl, whisk together flour and baking powder. Gradually add this mixture to the yolk mixture and beat with the hand whisk until smooth and lump-free.
In the bowl of a stand mixer, beat the egg whites until frothy. Add the cream of tartar and beat until soft peaks form. Add the sugar gradually while the mixer is running and continue to beat until stiff peaks form. Fold the beaten egg whites (meringue) into the yolk batter in three additions using a rubber spatula until the color of the batter is uniform.
Pour and scrape the batter into the prepared baking pan. Bake for 10-12 minutes. Slide the cake with the parchment paper backing into a wire rack and allow to cool completely.
Beat together whipped cream, icing sugar, and ube extract in the bowl of a stand mixer until thick and fluffy.
Once the cake is cool, remove the parchment backing. Place a piece of parchment paper that is slightly larger than your cake over it, and top it with a baking pan of the same size or larger.
Invert everything over. Gently peel off the parchment paper from the cake. To turn the cake to its top side again, position another parchment paper on top, followed by another baking pan. Invert the cake once more.
Serving Size 4-6 servings