2) In a mixing bowl, add egg yolks, banana extract, bourbon and 2 cups of sugar and whisk together until the mixture is pale yellow in color and thickened. Add cornstarch and mix to combine. Very slowly pour in a little of the milk mixture, you have to do it slowly to temper the mixture, (otherwise the eggs will scramble). Once fully incorporated pour the entire mixture back into the pot and place over medium heat. Stir constantly until it comes to a simmer and the mixture thickens enough that it coats the back of a wooden spoon. Remove from heat and add a pinch of salt and vanilla essence, then add butter cubes and stir to make the mixture rich and super glossy.
3) Transfer to a bowl and cover with plastic wrap, pressing the wrap onto the surface so it doesn't form a skin on the surface. Allow to cool.
4) In a large bowl, using a hand mixer, whip the cream with 50g of sugar and a splash of vanilla essence until you have stiff peaks. Set aside.
5) Slice bananas and add to pastry cream.
6) Line a small deep rectangular dish or a 25-cm pie dish with vanilla wafers. Splash with more creme de banana then cover with banana pastry cream. Top with whipped cream and refrigerate until ready to serve.