Make the ginger cookie crust:
Preheat the oven to 325°F. Set aside 1 tablespoon of ginger cookie crumbs if using for garnish. In a bowl, combine the remaining cookie crumbs and the melted butter. Stir to combine completely. Once all the crumbs are moistened, pour the mixture into a 9-inch pie pan. Then using a flat-bottomed cup, press the crumbs evenly into the pan across the bottom. The edges of the shell will be rustic and crumbly. Bake for 9 minutes, cool completely.
Make the protein packed pastry cream:
Over a small bowl, sift the remaining sugar an date cornstarch together. In a large bowl, whisk together the egg and egg yolks.
When the milk mixture comes to a simmer, add the cornstarch mixture to the eggs and whisk until combined.
While whisking the egg mixture constantly, slowly drizzle in about 3/4 cup of the milk mixture to temper it. Transfer this mixture into the saucepan, over low heat. Simmer, whisking constantly, until it reaches the consistency of thick pudding. ***This will seem like it is taking forever - I timed it at about 20 minutes to come to pudding consistency for me. Be careful and don’t get impatient in this step. If the mixture gets too hot or cooks to long you risk curdling the eggs but if it doesn’t cook long enough your pie filling will not set.***
Once pudding like remove from the heat and stir in the butter until incorporated. Pour the protein packed pastry cream into a shallow bowl, place plastic wrap directly on the surface and chill.
Using an electric mixer or whisk, whip the heavy cream and vanilla into peaks Transfer the chilled pastry cream to a large bowl and whisk until smooth. Fold in 1/2 cup of the whipped cream. Line the bottom of the cooled cookie crust with an even layer of sliced bananas. Fold the remaining banana slices into the pastry cream, then spoon it evenly into the crust. Mound the remaining whipped cream on top, swirling it decoratively. Chill completely, about 4 hours, then serve within 24 hours.