Whisk the flour, baking powder, baking soda, and salt together.

Beat the butter, vegetable oil, and sugar together with a mixer at medium speed for about 2 minutes until the mixture is fluffy and doubled in size.

Add the eggs, one at a time, making sure one egg is completely incorporated before adding the next one.

Add the vanilla and passionfruit pulp.

Mix to combine.

Add one third of the flour mixture to the bowl. Mix on low.

Add half of the buttercream, and mix to combine.

Then add another third of the flour mixture and mix briefly.

Add the remaining buttermilk and mix.

Finish with another 1/3 of the flour mixture and stir to combine.

Divide the cake batter evenly between the 3 cake pans.

Bake in the pre-heated oven for 25 to 30 minutes, until a toothpick comes out clean when inserted in the cake, or once you touch the cake and it bounces right back.

Let the cakes cool down for 10 minutes.

Then flip the cakes onto a wire rack to cool down.

If not assembling the cake on the same day, wrap the cakes individually in plastic wrap and place them in the fridge or freezer. They will store well in the freezer for up to 2 months, or in the fridge for up to 2 days.

Beat the butter, sugar, and salt for 30 seconds to one minute until incorporated.

Pour the passion fruit pulp in the bowl and mix. Mixture will seem curdled and separated, and that’s ok.

Transfer it to a small saucepan with a heavy bottom.

Start cooking at low heat, stirring non-stop with a spatula.

Keep cooking for 5-10 minutes. Don’t let the mixture boil, and don’t stop stirring. Cook until the curd temps 170ºF.

The curd should be thick, coating the back of a spoon.

Depending on how high or low the heat is, the time will vary. You don’t want the eggs to boil, and you don’t want the mixture to stick to the bottom of the pan, which will easily happen if the heat is too high, or if you stop stirring.

Once the curd is ready, pour it into a heat-proof bowl, and let it cool down.

You can add passionfruit seeds to the curd and mix for an added crunch element.

Place it in the fridge for at least 6 hours to chill through and get thick.

The curd can be stored in the fridge for up to 4 days, or in the freezer for up to 1 month.

The passionfruit syrup is an optional step, but I find that really helps enhance the passionfruit taste in the cake. It makes the layers moist and brimming with passionfruit flavor.

To make the syrup, simply place the passionfruit pulp and the sugar in a small saucepan and bring to a boil over medium heat.

Once the sugar melts, turn the heat off. Let the syrup cool down before assembling the cake.

You can store this syrup in the fridge for up to 15 days. Or use it to sweeten drinks.

Whisk the egg whites and the sugar in a large glass bowl.

Place the bowl over a double boiler with barely simmering water. Make sure the bottom of the bowl isn’t touching the water.

Whisk the sugar and whites until the sugar melts and a thermometer reads 140ºF.

Remove and transfer the syrup to the bowl of a stand mixer, or start whipping the syrup with a hand mixer.

Whip on medium high for about 10 minutes, or until stiff peaks form. Depending on the mixer or speed used, it can take even up to 18 minutes.

If the mixture isn’t reaching stiff peaks, place the bowl in the fridge for 5 to 10 minutes and then start whipping again.

Continue whisking until it becomes creamy and thick.

Add the vanilla and mix.

If the buttercream is too thin and not coming together, place the whole bowl in the fridge for 10 minutes, and then whip it again until thick.

Switch to the paddle attachment and mix the buttercream on low for 20 minutes. This will get rid of air bubbles and make such a smooth and silky buttercream.

If you are using a hand mixer and don’t have the paddle attachment, simply mix the buttercream with a spatula pressing it against the sides of the bowl to deflate it. Try to do this as long as possible, for about 5 to 10 minutes or as much as your arms can take it. It’s worth doing it.

Place one layer of Passionfruit Cake on a cake plate.

Brush the top of the cake with the syrup, and wait a minute for the cake to soak up all the syrup.

Spread a very thin amount of Swiss Meringue Buttercream on the cake.

Place some of the Swiss Meringue Buttercream in a piping bag fitted with a round tip.

Pipe a ring of frosting around the edges of the cake layer.

Fill the center with 1/3 to 1/2 cup of passionfruit curd.

Top with another cake layer and repeat the process.

Once all layers are stacked, spread a thin amount of frosting on top of the cake and around the sides. Use a bench scraper to smooth out the sides, and use an offset spatula to scrape the excess from the top.

Place the cake in the fridge for about 20 minutes.

Remove the cake from the fridge and spread a generous amount of frosting on top and on the sides of the cake.

I used a comb to make the sides of the cake scalloped.

Then I put the frosting in a piping bag fitted with a tip 4B, and piped a rope around the edges on top of the cake. Place the cake in the fridge.

Once the cake was cold and the frosting had set, I spread passionfruit seeds with the pulp on top of the cake

Store the cake in the fridge covered for up to 3 days.

To freeze: slice individual slices and wrap each individually in plastic wrap, place in an airtight container or freezer bag, and freeze for up to 3 months.

You can also freeze the whole cake. I made miniature cakes from this recipe and froze the whole frosted mini cake by wrapping it in plastic and placing in an airtight container in the freezer.