Introduction

This Custard Cake features a rich vanilla pastry cream layered between moist, tender vanilla cake with a silky custard buttercream frosting. It’s a perfect dessert for celebrations or a special treat, combining creamy custard and classic cake textures for a truly indulgent experience.

A slice of three-layer vanilla cake with light yellow sponge and creamy white frosting between each layer sits on a white plate with a small portion on a fork beside it. The cake is covered in smooth white frosting and topped with a swirl of frosting decorated with small dark chocolate curls. The scene is set on a white marbled surface with a simple light gray background, and part of the full frosted cake on a white cake stand is visible in the background. Photo taken with an iphone --ar 4:5 --v 7

Ingredients

For the Vanilla Pastry Cream:

3 cups Whole Milk (710g / 720ml)
1 tablespoon Vanilla Extract
7 Egg Yolks
¾ cup Granulated Sugar (150g)
6 tablespoons Cornstarch
1 ½ sticks Unsalted Butter (170g)

For the Vanilla Cake:

1.25 cups Whole Milk (300g / 300ml)
⅓ cup Vegetable Oil (66g / 80ml)
3 Large Eggs
2 ¾ cups Cake Flour (312g)
1 ¾ cups Granulated Sugar (350g)
1 tablespoon Baking Powder
½ teaspoon Salt
1 teaspoon Vanilla Extract
2 sticks Unsalted Butter (227g)

For the Custard Buttercream:

⅔ batch Vanilla Pastry Cream (prepared for the filling)
4 sticks Unsalted Butter (454g)
⅓ cup Powdered Sugar (38g)
1 teaspoon Vanilla Extract
¼ teaspoon Salt

Instructions

Make the Pastry Cream (Custard):
Make the pastry cream 2 to 24 hours ahead to allow it to cool and thicken. Whisk together egg yolks, sugar, and cornstarch in a bowl until pale and thick. In a saucepan, heat milk and vanilla over medium heat until steaming with tiny bubbles (do not boil). Gradually whisk a small amount of hot milk into the egg mixture to temper it, then combine all and return to the saucepan. Heat, whisking constantly, until it boils and thickens—about 1 to 2 minutes—then remove from heat. Pass through a sieve if lumps form. Whisk in butter piece by piece until smooth. Cover with plastic wrap directly on the surface and refrigerate for at least two hours or overnight.
Make the Vanilla Cake:
Preheat oven to 350°F (180°C; 160°C fan-assisted). Grease two 8-inch cake pans. Bring butter, eggs, and milk to room temperature. Divide the milk into two portions: ½ cup and ¾ cup. Mix ½ cup milk with vegetable oil and set aside. Whisk together the remaining milk, eggs, and vanilla. In a mixer bowl, combine flour, sugar, baking powder, and salt. Add butter in small pieces and mix on low until resembling coarse crumbs. Gradually add the milk-oil mixture and beat on medium for two minutes. Scrape bowl, then add milk-egg mixture slowly and mix on low until just combined. Divide batter into pans and bake 30–40 minutes or until a toothpick comes out clean. Cool in pans for at least 30 minutes before removing.
Make the Custard Buttercream:
About an hour before assembling, move ⅓ of the pastry cream to a bowl, cover, and refrigerate. Leave the remaining ⅔ covered at room temperature. Also, bring butter to room temperature. Using a mixer, beat the butter on high until pale and fluffy (3–5 minutes). Add room-temperature pastry cream one tablespoon at a time, whipping between additions until fully incorporated. Mix in vanilla and salt. Taste the buttercream and add powdered sugar slowly, whipping after each addition, until the desired sweetness is achieved. The buttercream should be smooth; if curdled, check that ingredients are at the same temperature.
Assemble the Cake:
Once cakes are completely cooled, slice each horizontally to create four layers. Start layering: place a cake layer, spread custard buttercream evenly, then add the second cake layer with a thinner layer of buttercream. Pipe a buttercream border around the edge of this layer and fill the center with half of the cold reserved pastry cream. Add the third cake layer on top, followed by another generous buttercream layer, then the final cake layer. Decorate as desired with rosettes of buttercream around the top edge. Pour the remaining cold custard into the center of the cake within the rosettes.

Tips & Variations

Make the pastry cream a day ahead for best flavor and ease of assembly.
If the buttercream curdles, try warming the bowl slightly or mixing gently until smooth again.
For a lighter cake, substitute half the butter with Greek yogurt or sour cream in the cake batter.
Use a cake leveler or a serrated knife for even, clean slices of cake layers.

Storage

Store the assembled cake covered in the refrigerator for up to 3 days to keep the custard fresh. Let the cake sit at room temperature for 15-20 minutes before serving for the best texture. Leftover cake can be frozen wrapped tightly for up to one month; thaw overnight in the fridge before serving.

How to Serve

The image shows a close-up of a slice of cake with two layers—an inner soft, light cream-colored cake layer and a thin dark filling layer in between. The outside is covered with smooth white frosting. On top, there is a large puff of piped white frosting swirled in a tall spiral, decorated with small dark chocolate pieces scattered around the top and side. The cake rests on a white marbled surface. Photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I make the pastry cream without cornstarch?

Cornstarch is essential for thickening the pastry cream properly. Without it, the custard may remain too runny. If unavailable, you can try using flour, but the texture and clarity might differ.

How do I prevent the custard from curdling when mixing the buttercream?

Ensure all ingredients—pastry cream and butter—are at the same room temperature before mixing. Adding the cream slowly and beating well also helps maintain a smooth, stable buttercream.