Spongy, airy, creamy, chewy—boba lava cake has it all! This dessert features a beautiful sponge cake topped with milk tea-infused custard and boba pearls. All this decadence is held together by a sheet of acetate (the plastic film pastry chefs use to decorate cakes). Once that acetate is lifted, there’s an outpouring of custard running down the sides, comparable to the ever-popular science fair volcano experiment.
When my kids were little, we made volcanoes every chance we got. Once, we even made a snow volcano together. This sparked the idea of creating an edible volcano that we could enjoy after the eruption. That inspiration led to my Volcano Mayo Chocolate Cake, where chocolate ganache oozes out of the center when you cut it.
That cake was great, but there is something absurdly decadent about boba lava cakes, starting with the fact that it’s a mash-up of three top-tier sweet treats. I used this recipe from Nino’s Home for inspiration, and although it is a pretty detailed recipe with a few components, the cake will turn out amazing if you follow the instructions.
In the end, you’ll have a delicious cake. The flavor of the tea comes through beautifully, infusing both the cake and the custard. The bitterness of the tea counterbalances the sweetness of the dessert perfectly, and the complexity of brown sugar from the boba complements the other flavors very well.
Boba Lava Cake
Equipment
- 1 Electric hand mixer
- 2 Mixing bowls one large, one medium
- 1 spatula
- 1 whisk
- 1 PushPan 9 inch, circular
- 1 Sauce pan
- 1 Offset spatula
- 1 Rack for cooling cake
- 1 clear acetate sheet 4 inch wide
Ingredients
Milk Tea
- 1.125 cups whole milk 250mL, or 1 cup plus 2 tablespoons
- 6 tbsp 20g loose-leaf black tea
Cake
- 3 eggs room temperature — yolks and whites separated
- 2 ½ ounces milk tea 50mL
- 2 tbsp vegetable oil 20g
- ½ cup cake flour 70g
- ½ tsp black tea powder
- ¼ tsp lemon juice fresh
- .375 cup granulated sugar 65g, or a quarter cup plus 2 tablespoons
Lava Cream
- 1 egg yolk
- 3 ½ ounces milk tea 120mL
- ¼ cup muscovado sugar 40g
- 1 tbsp cornstarch 5g
- 1 cup whipping cream 200g
Boba
- 1/3 cup 5-minute boba 50g I used WuFuYuan brand 5-minute Boba
- 2 tbsp muscovado sugar 20g
Instructions
Milk Tea
- Add the milk and tea to a saucepan and bring to a boil.
- Remove from the heat, cover, and let the milk tea steep for 20 minutes.
- Strain the milk tea to remove the solids and set the milk tea aside.
Cake
- Preheat oven to 320°F (160°C).
- Add the egg whites to one mixing bowl and the yolks to another.
- To the egg whites, add the measured milk tea, oil, cake flour, and black tea powder (I used the powder from a black tea bag).
- Whisk until well combined.
- Add lemon juice to the bowl with the egg whites. Beat with an electric mixer until frothy.
- Sprinkle half the sugar into the egg whites. Beat until white and frothy.
- Add the remaining sugar and continue to beat until you have firm peaks.
- Whisk some of the meringue into the bowl with the egg yolk mixture. Doing so lightens it up, which makes it easier to fold into the meringue.
- Pour the egg yolk mixture into the meringue and gently fold until well combined. Work slowly to avoid losing any of the volume.
- Pour the batter into a non-greased push pan, then give the pan a few swift taps on the counter. It is important not to grease the pan, as doing so will prevent the cake from rising.
- Transfer to the oven to bake for 50 minutes.
Lava Cream
- While the cake is baking, make the milk tea custard cream. (Start on this sooner rather than later because it requires some refrigeration.)
- To start, add an egg yolk to a small saucepan.
- Pour in the milk tea, then follow with the brown sugar and cornstarch.
- Over medium heat, whisk the mixture until a thick paste forms.
- Transfer the paste to a bowl, cover it, and refrigerate it for 30 minutes.
- In a clean mixing bowl, pour heavy cream. Whisk until slightly thickened.
- Loosen up the paste, and then add it to the cream.
- Vigorously whisk until you have a thick, rich custard cream.
Boba
- Bring a pot of water to a boil.
- Add the boba and simmer for 5 minutes.
- Strain and add the boba to a bowl with the sugar. Stir to both coat the boba in sugar and create an instant syrup.
Assembly
- Run an offset spatula around the cake’s edge and remove it from the pan. Transfer the cake to a cooling rack.
- Once cooled, place the cake onto a cake stand, then position a 4-inch-wide piece of acetate around the cake. Secure it with tape. Make sure the fit is pretty tight.
- Add the lava cream to the top of the cake, and then plop the boba on top.
- Lift the acetate so the cream and boba cascade over the sides like lava. (If you're like me and overbeat the cream a bit, you may need to use a spoon or spatula to coax it over the edge.)
- Slice & serve!
