Preheat oven to 325°F (165°C). In a small saucepan over medium heat, combine 3/4 cup sugar and water. Swirl the pan gently without stirring until the mixture turns deep amber, about 8-10 minutes. Immediately pour into a 9-inch round cake pan or flan mold, tilting to coat the bottom evenly. Set aside to harden.

In a blender, combine eggs, sweetened condensed milk, evaporated milk, passion fruit pulp, remaining 1/4 cup sugar, vanilla extract, and salt. Blend on medium speed for 30-45 seconds until smooth and well combined, but avoid over-mixing which creates bubbles.

Pour the custard mixture through a fine-mesh strainer into the prepared pan with caramel. This removes any egg bits and ensures silky texture. Use a spoon to skim off any surface bubbles.

Place the flan pan inside a larger roasting pan. Carefully pour hot water into the roasting pan until it reaches halfway up the sides of the flan pan, creating a water bath.

Bake for 55-65 minutes, until the edges are set but the center still jiggles slightly when gently shaken. The custard will continue setting as it cools. Remove from water bath immediately.

Let cool to room temperature on a wire rack for 1 hour, then cover with plastic wrap and refrigerate for at least 8 hours or overnight. The flan must be completely chilled to unmold properly.

To serve, run a thin knife around the edges of the pan. Place a rimmed serving plate over the pan, then quickly invert both together. Lift the pan off slowly, allowing the caramel sauce to drizzle over the custard. Slice into wedges and spoon extra caramel sauce over each portion.