Whisk the passion fruit puree, sugar, egg yolks, whole egg and salt in a saucepan over medium-low heat. Stir constantly until thick enough to coat a spoon, then remove from the heat and stir in the butter. Cover the surface and refrigerate until cold.
Heat the oven to 350 F. Grease and line two 8-inch round cake pans, then whisk together the cake flour, baking powder and salt.
Beat the butter and sugar until very light and fluffy. Beat in the eggs one at a time, then blend in the vanilla and coconut extract.
Whisk the coconut milk and sour cream together. Add the dry ingredients to the butter mixture in three additions, alternating with the coconut milk mixture, and mix just until smooth.
Divide the batter between the pans and bake for 28 to 33 minutes, until the centers spring back when lightly pressed. Cool in the pans for 15 minutes, then turn out and cool completely.
Beat the cream cheese and butter until smooth. Gradually beat in the powdered sugar, then add the coconut milk, vanilla and salt and beat until fluffy.
Pipe a ring of frosting around the edge of the first cake layer and fill the center with the chilled passion fruit curd. Add the second cake layer, then cover the top and sides with the remaining frosting.
Press the toasted coconut over the sides of the cake. Spoon the passion fruit pulp over the top shortly before serving.