Preheat oven to 350F. Grease the bottom of a 10x15 inch jelly roll pan then line with parchment paper. Set aside.
In a medium bowl, sift the cake flour, baking powder and salt. Set aside.
In a large bowl using an electric hand mixer or using a stand mixer with the whisk attachment, combine egg yolks, maple syrup, ube extract, water and sugar on high speed until thick and incorporated (8-10 minutes).
In another bowl using clean whisks, whisk egg whites with cream of tartar on low-medium speed until foamy.
Gradually add the sugar - about a tablespoon at a time - until you reach stiff peaks.
Add half of the meringue mixture to the egg yolk mixture and gently fold until well blended. The batter should be light and airy.
Add flour mixture to cake batter in 3 equal parts, gently folding each addition until combined.
In a small microwave-safe bowl or measuring cup, microwave the oil in 10-second increments until the bowl is warm (not hot) to the touch.
Add about ¼ cup of cake batter to the oil and mix until incorporated.
Add back the oil mixture into the cake batter and fold until well blended.
Finally, add the rest of your meringue to the cake batter and fold in gently.
Baking and cooling
Pour the cake batter into your prepared pan. Gently tap on your counter a few times to release air bubbles and to help the batter settle in.
Bake for 20-25 minutes or until the cake springs back when gently pressed and a toothpick inserted in the centre comes out clean.
While the cake is still warm, run a thin sharp knife around the edges of the pan, place a clean, slightly damp kitchen or tea towel on top, and carefully invert.
Lift the pan up and peel off the parchment paper.
Optional: if making ube crumbs, slice a strip of cake an inch wide from the long side and 2 inches wide from the short side. Set aside to cool (directions for ube crumbs follow).
Roll the rest of the cake and place on your counter seam side down. Allow the cake to cool completely before un-rolling and frosting.
Whipped cream cheese frosting
In a large bowl using a handheld electric mixer or using a stand mixer fitted with the paddle attachment, beat cream cheese on medium-high speed until creamy (about 2 minutes).
Add sugar and salt and beat until incorporated.
If using a stand mixer, switch to the whisk attachment and add the heavy cream in a steady stream and continue to beat until you reach stiff peaks. Scrape the bottom and sides of your bowl. Use immediately. Otherwise, store in the fridge.
When the cake has completely cooled, unroll and fill with frosting. Spread evenly but not too thickly; no more than ¼ inch.
Re-roll the cake using the tea towel to help you push the cake over.
Then frost the outside of the cake, cover with crumbs (if using), and decorate as desired. Chill in the fridge at least 2 hours before serving.
To make ube crumbs
Put the strips of cake in a food processor and pulse until you get fine crumbs. You can also manually crumble with a fork.
Serving size depends on how thick you slice the cake. The estimated nutrition information is based on 8 servings.
When making the meringue, don't go beyond medium speed (I stay on speed 3 using my KitchenAid stand mixer). This ensures your meringue is stable and less likely to deflate after baking.
Make sure to use cold cream cheese and cold cream when making the frosting.
Did small bubbles form on the surface of your cake? That's usually the result of the baking powder doing its thing, or sometimes over-mixing. Don't worry, we'll cover that with frosting.
Did your cake crack while rolling? That's common with rolled cakes and takes time to master. Again, don't worry as the delicious frosting will hide all those cracks and nobody will ever know.
See the post for lots more baking tips, FAQs and step-by-step photos.