Japanese castella cupcakes are soft, fluffy, and gently sweet—a total joy to make and eat. Let’s do this properly, step by step, with all the little tips that make them bakery-level ✨
🍰 Japanese Castella Cupcakes (Kasutera-Style)
Yield
8–10 cupcakes (depending on liner size)
🧾 Ingredients
Wet ingredients
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4 large eggs, room temperature
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120 g (½ cup + 1 tbsp) granulated sugar
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60 ml (¼ cup) honey
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40 ml (3 tbsp) milk, warm
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60 ml (¼ cup) neutral oil (vegetable or canola)
Dry ingredients
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120 g (1 cup) cake flour
or: 105 g all-purpose flour + 15 g cornstarch -
½ tsp salt
🛠 Equipment
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Muffin tin
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Cupcake liners
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Fine sieve
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Hand mixer or stand mixer
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Rubber spatula
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Baking tray (for water bath)
🔥 Step-by-Step Directions
1️⃣ Prepare the oven & pan
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Preheat oven to 160°C / 320°F
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Line your muffin tin with cupcake liners
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Place a baking tray on the lower rack (you’ll add hot water later)
👉 Why: Castella likes gentle, moist heat—this keeps it fluffy and crack-free.
2️⃣ Warm the honey mixture
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Mix honey + warm milk until fully dissolved
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Set aside to cool slightly
👉 Warm milk helps the honey blend smoothly and evenly.
3️⃣ Whip eggs and sugar (very important)
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In a large bowl, add eggs + sugar
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Beat on high speed for 5–7 minutes
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Mixture should:
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Turn pale
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Triple in volume
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Form ribbons that sit on the surface for a few seconds
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👉 This step creates the structure—no baking powder needed.
4️⃣ Add oil & honey mixture
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Lower mixer speed to low
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Slowly drizzle in:
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Oil
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Honey-milk mixture
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Mix just until combined
👉 Don’t overmix here—you want to keep the air.
5️⃣ Sift and fold in dry ingredients
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Sift cake flour + salt
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Add in 2–3 batches
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Fold gently using a spatula (cut down, scoop up, rotate bowl)
👉 Stop as soon as you don’t see dry flour.
6️⃣ Fill the cupcake liners
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Pour batter into liners until 80–85% full
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Tap the pan gently once to remove large air bubbles
7️⃣ Water bath baking
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Place cupcake tray in oven
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Carefully pour hot water into the lower tray (about 1–2 cm deep)
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Bake at 160°C / 320°F for 20–25 minutes
👉 If tops brown too fast, loosely tent with foil.
8️⃣ Check doneness
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Insert a toothpick—should come out clean
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Tops should be:
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Light golden
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Slightly springy to touch
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9️⃣ Cool properly
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Remove from oven
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Let cool in pan for 5 minutes
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Transfer to rack
👉 For ultra-moist texture, loosely cover with plastic wrap once warm.
✨ Pro Tips for Perfect Castella Cupcakes
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Room-temperature eggs whip better
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Weigh ingredients for best results
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Gentle folding = fluffy crumb
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Water bath = moist interior, flat tops
🍯 Optional Variations
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Matcha: Add 1½ tsp matcha powder (reduce flour by same amount)
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Chocolate: Add 15 g cocoa powder + extra 1 tbsp milk
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Cheese-filled: Pipe sweetened cream cheese into center after baking