CRUST

1. Preheat the oven to 350°F (roughly 180°C).
2. In a blender, pulse the Biscoff cookies until all the pieces are smaller than a quarter coin. 
3. In a mortar and pestle, grind the fennel seeds into smaller pieces for roughly a minute. 
4. Melt the butter in the microwave, and add in the cookie crumb, the ground fennel seeds, sugar, and salt, mixing to combine. 
5. Spray a pie dish with nonstick cooking spray, and add in the crust mixture. First use your hands to evenly distribute the crust mixture, and then use the flat bottom of a glass to gently press down the mixture along the bottom and sides of the dish until the crust is compact. 
6. Bake the crust in the preheated oven for 8-10 minutes, until the crumb is firm and holds together. Set aside and leave to cool completely.  

FILLING

1. Put the passion fruit pulp in a food processor and blend for a minute, until all the seeds have separated from the pulp. Strain through a fine mesh strainer into a bowl, using a spoon to push through the thicker pulp, until only the seeds remain in the strainer. 
2. Add the lime juice and lime zest to the bowl with the passion fruit pulp. 
3. In another bowl, beat the egg yolks with an electric whisk until they are pale and fluffy. Whilst whisking, slowly pour in the condensed milk until fully incorporated. 
4. Slowly fold in the passion fruit and lime mixture until fully incorporated. 
5. Pour the mixture into the cooled pie crust, and bake in the oven until it has mostly set, roughly 8 minutes. The pie should still wobble when you move it. 
6. Let the pie finish setting by chilling in the fridge for 4-6 hours (or ideally overnight), until the pie is no longer wobbly. 

DECORATION

1. Before serving, add whipped cream to the pie, dust with powdered sugar, and garnish with freshly grated lime zest.