Shape the Crust: Mix crushed biscuits with melted butter until sandy. Press firmly into the base and sides of a tart pan. Chill for 20 minutes to set.
Warm the Coconut Base: In a saucepan, heat coconut milk and heavy cream over medium-low heat until just steaming—never boiling.
Build the Cream: In a bowl, whisk egg yolks, sugar, and cornstarch until smooth. Slowly pour in the warm coconut mixture, whisking constantly.
Thicken Gently: Return everything to the saucepan. Cook on low heat, stirring continuously, until the cream thickens and holds soft peaks. Fold in shredded coconut and vanilla.
Fill and Smooth: Pour the hot cream into the chilled crust. Smooth the surface and let it cool slightly.
Chill to Set: Refrigerate for at least 4 hours, until fully firm and sliceable.
Finish with Texture: Before serving, sprinkle generously with toasted coconut for a crisp contrast.
