Passionfruit Cake

Passionfruit Cake Layers:

1. Preheat the oven to 350°F. Grease three 8-inch cake pans, line with parchment paper, and grease the paper.
2. Whisk together the flour, baking powder, baking soda, and salt.
3. In a mixer, beat butter, vegetable oil, and sugar on medium speed for 2 minutes until fluffy.
4. Add eggs one at a time, mixing well after each.
5. Add vanilla and passionfruit pulp, mixing to combine.
6. Add a third of the flour mixture, mixing on low.
7. Add half the buttermilk, mix to combine.
8. Add another third of the flour mixture, mix briefly.
9. Add the remaining buttermilk, mix.
10. Finish with the remaining flour mixture, stir to combine.
11. Divide the batter evenly between the cake pans.
12. Bake for 25-30 minutes, until a toothpick comes out clean.
13. Cool in pans for 10 minutes, then transfer to a wire rack to cool completely.
14. Wrap in plastic wrap and refrigerate or freeze if not assembling the same day.

Passionfruit Curd:

1. Beat butter, sugar, and salt for about 1 minute.
2. Add egg yolks, mix to combine.
3. Pour in passionfruit pulp, mix (it may look curdled, that’s okay).
4. Transfer to a saucepan and cook on low heat, stirring constantly, until it thickens and reaches 170°F.
5. Pour into a heat-proof bowl to cool.
6. Chill in the fridge for at least 6 hours. Store up to 4 days or freeze for up to 1 month.

Passionfruit Syrup:

1. Combine passionfruit pulp and sugar in a small saucepan.
2. Bring to a boil over medium heat until sugar dissolves.
3. Cool before using. Store in the fridge for up to 15 days.

Swiss Meringue Buttercream:

1. Whisk egg whites and sugar in a heat-proof bowl over a simmering double boiler.
2. Whisk until sugar melts and the mixture reaches 140°F.
3. Transfer to a mixer and beat on medium-high for about 10 minutes until stiff peaks form.
4. Cool to 70-75°F if necessary.
5. Add butter, one tablespoon at a time, mixing well after each.
6. Mix until creamy and thick.
7. Add vanilla and mix.
8. If too thin, chill for 10 minutes and whip again.
9. Switch to the paddle attachment and mix on low for 20 minutes.

To Assemble the Cake:

1. Place a cake layer on a cake plate.
2. Brush with syrup and wait a minute for it to soak in.
3. Spread a thin layer of buttercream over the cake.
4. Pipe a ring of buttercream around the edge.
5. Fill the center with 1/3 to 1/2 cup of passionfruit curd.
6. Repeat with remaining layers.
7. Frost the top and sides of the cake. Chill for 20 minutes.
8. Apply a final generous layer of frosting. Smooth with a bench scraper and offset spatula.
9. Decorate with frosting and passionfruit seeds if desired.