Cook the custard: Return the mixture to the saucepan and cook over medium heat, stirring constantly, until thickened and bubbly, about 5-7 minutes. Remove from heat and let cool slightly.
Assemble: Pour the custard over the cooled crust and spread into an even layer. Refrigerate for at least 2 hours, or until the custard is set.
Make the Whipped Cream: In a large bowl, beat the heavy cream, powdered sugar and vanilla extract until stiff peaks form.
Top and Serve: Spread the whipped cream over the custard layer, creating a smooth, even top. Cut into squares to serve. Garnish with whipped cream or white chocolate shavings if desired. Serve chilled.
Prep time: 20 minutes | Total time: 40 minutes (plus resting time) | Servings: 9 servings
