Preheat the oven to 350°F (175°C). Grease and flour a 9-inch round cake pan.
In a large mixing bowl, combine the flour, sugar, baking powder, and salt.
Add the passion fruit puree, melted butter, milk, eggs, and vanilla extract to the dry ingredients. Mix until well combined.
Pour the batter into the prepared cake pan and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool completely before glazing.
Prepare the passion fruit mirror glaze (recipe below).
Place the cooled cake on a wire rack set over a baking sheet to catch excess glaze.
Pour the mirror glaze over the cake, ensuring it covers the top and sides evenly.
Decorate the top of the cake with passion fruit seeds.
Allow the glaze to set before serving.