Preheat the oven to 325°F.

Grease and line 3 6-inch round cake pans with parchment paper. Set aside.

Sift the flour, baking powder, and salt together in a large mixing bowl. Whisk to combine and set aside.

Place the butter and the sugar in a large stand mixer fitted with a paddle attachment. Cream the sugar into the butter until light and fluffy. Add the eggs 1 at a time, holding off until each egg is fully incorporated before adding another.

Add a 1/3 of the flour mixture to the batter and beat until fully incorporated. Next, add 1/2 of the buttermilk. Continue in this pattern until all of the buttermilk and the flour mixture is integrated.

Decrease the speed of the mixture and add the chocolate chips and nuts. Stir until evenly dispersed.

Using an ice cream scoop, divide the batter amongst the 3 cake pans. Tap the pans on the counter to eliminate any air bubbles.

Transfer the cakes to the oven and bake for 35-40 minutes or until a toothpick an be cleanly inserted in the center of each cake.

Let the cakes cool in their pans for 10 minutes before removing them and placing them on a cooling rack to let cool completely.

When the cakes have cooled, wrap them tightly in plastic wrap and transfer the layers to the fridge until ready to decorate.

Halve the passion fruit and scoop out the pulp. Place the pulp in a food processor and pulse to separate the membrane from the seeds. But don't blitz so much that you crack the seeds.

Pour the contents of the food processor into a fine mesh strainer. Separate the juice from the solids and set both aside.

Pour the juice into a small saucepan and add the salt and sugar. Stir until the sugar starts to dissolves. Add the egg yolks and whisk until well integrated.

Place the saucepan over medium heat and bring to a low simmer while whisking constantly. Cook until the curd is thick enough to coat the back of the spoon readily. About 7-10 minutes. Take the saucepan off of the heat and stir in the butter. Whisk until the butter has melted and is fully integrated. Next, stir in a heaping tablespoon of the reserved passion fruit seeds.

Let the curd cool to room temperature before transferring it to a bowl. Cover with plastic wrap and chill for at least 3 hours.

Place the butter in a large stand mixer fitted with a whisk attachment. Whisk on a high speed until the butter becomes fluffy and turns nearly white.

Slowly add the confectioner's sugar, taking care to lower the speed of the mixer with each new addition.

Now, if you are coloring the buttercream as pictured, place 6 ice cream scoops worth of the buttercream in a large bowl and set aside. Place 3 scoops of buttercream in 3 smaller bowls and set aside.

Take a 1/3 of the cream and a 1/3 of the coconut extract and whip it into the large bowl of buttercream. Divide the remaining cream and extract amongst 3 small bowls. Add a small amount of yellow color gel to one bowl, blue to another, and peach to the other. Whisk the colors into the cream and extract and pour over each of the three smaller bowls of buttercream. Whisk until integrated.

Level each of the cake layers so they are even.

Place a dollop of buttercream on a cake drum and place the drum on a turn table. Place the first layer of cake on top of the buttercream.

Transfer the uncolored buttercream to a large piping bag with a wide round nozzle. Pipe a border of buttercream on top of the first layer cake. Spoon passion fruit curd into the center of the border.

Place the second layer of cake on top of the first and pipe another buttercream border and add some more curd. Place the third cake layer on top. Ice the cake with thin crumb layer of uncolored buttercream. Transfer the cake to the fridge and chill for 1 hour.

Take the remaining buttercream and place each color in separate small piping bags, each with their own unique nozzles. Pipe the colored buttercream all over the cake in a pleasing fashion. Fill any holes with white chocolate chips and macadamia nuts.

Finish the cake with fresh-cut organic flowers and serve immediately or chill until ready to serve. Be sure to let the cake sit at room temperature for 30 minutes before slicing.