Prepare to experience the ultimate cotton-soft, melt-in-your-mouth sensation! Known for its signature jiggly texture and pillow-like fluffiness, this traditional Taiwanese Castella Cake is a masterpiece of airy baking. By combining a warm oil-and-flour emulsion with a perfectly whipped meringue, you get a beautiful golden crust and an interior that practically dissolves on your tongue.
🛒 Ingredients
- 4 large eggs (separated into whites and yolks, at room temperature)
- 60g (½ cup) cake flour, sifted
- 50g (approx. 4 tbsp) neutral vegetable oil (like canola or corn oil)
- 70ml (approx. ¼ cup + 1 tbsp) whole milk
- 60g (approx. 5 tbsp) granulated sugar
- ¼ tsp cream of tartar or lemon juice (optional, to stabilize the egg whites)
- 1 tsp vanilla extract (optional)
👩🍳 Instructions
Step 1: Heat the Liquids and Prep
Preheat your oven to 300°F (150°C). Line a 6×6-inch (15×15 cm) square baking pan with parchment paper, allowing the paper to extend about an inch above the edges for easy removal later. In a small bowl, combine the vegetable oil and milk, then warm them in the microwave for 30 to 40 seconds until warm to the touch (around 120°F / 50°C), but not bubbling hot.
Step 2: Form the Base Batter
Sift the cake flour into a large mixing bowl. Pour the warm oil and milk mixture directly over the flour and whisk until completely smooth. Next, add the 4 egg yolks one by one (along with the vanilla extract, if using), whisking thoroughly after each addition until you have a glossy, pale yellow paste.
Step 3: Whip the Meringue
In a completely clean, grease-free glass or metal bowl, add the 4 egg whites and cream of tartar (or lemon juice). Begin whisking with a hand mixer on medium speed until frothy. Gradually add the sugar in small batches, continuing to whip on medium speed until the whites form smooth, soft but firm peaks that hold a gentle shape when the beaters are lifted.
Step 4: Fold with Care
Add about one-third of the whipped meringue into the egg yolk batter. Use a rubber spatula to fold it together gently using a circular “J” motion, cutting down the center and sweeping around the bowl. Once mostly combined, pour this mixture back into the remaining meringue and fold with a very light hand just until uniform in color. Do not overmix, or you will deflate the tiny air bubbles that make the cake jiggly!
Step 5: Setup the Water Bath (Bain-Marie)
Pour the batter from about 12 inches above the pan to pop any large air pockets naturally. Tap the pan firmly on the counter once or twice. Place your cake pan inside a larger, deeper baking tray. Pour hot water (around 175°F / 80°C) into the outer tray until it reaches about 1 inch up the sides of the cake pan.
Step 6: Bake and Release
Bake in the preheated oven at 300°F (150°C) for 50 to 55 minutes until the top is puffed and evenly golden brown. Carefully remove the cake pan from the hot water bath. Immediately lift the cake out of the pan using the overhang of the parchment paper and peel the paper away from the sides to prevent wrinkles.