In a medium bowl, add egg yolk, egg, ¼ cup plus 2 tablespoons sugar. Whisk until pale yellow in color. Set aside.
In a medium heavy-bottomed saucepan over medium heat, combine heavy cream, milk, ¼ cup sugar and vanilla bean paste. Bring to a gentle boil, whisking constantly to dissolve sugar. Remove from heat.
Whisk in ½ cup hot cream into the egg yolk mixture. Gradually add all the hot cream into the yolk mixture, whisking continuously. Return everything back to the saucepan. Cook over medium-low heat. Bring to a simmer and cook until thicken, about 7 – 8 minutes, stirring constantly with a large wooden spoon. The mixture will first turn into small lumps, then big lumps and eventually thicken. Once thicken, remove from heat and keep stirring until smooth, about 1 – 2 minutes. Strain the mixture through a fine-mesh into a medium bowl. Cover the custard with plastic wrap by pressing down to the surface. Chill in the fridge for 3 hours.
In a lightly floured surface, roll the pie crust to 1/8-inch thick. Put a 5½-inch ramekin on top. With a sharp knife, leave ½-inch space in between and cut a 6½-inch circle. Lift and gently fit the pie crust into the ramekin. Repeat with the other ramekin. For the 2-inch pies, cut 6 (4-inch) circles and fit into a mini muffin pan. If needed, gather the pie dough, form into a ball and roll into 1/8-inch thick again. Transfer the ramekins and muffin pan into the fridge to chill for at least 20 minutes. Prick the sides and bottom of the pie crusts with a fork.
Preheat the oven according to the directions on the package and bake until browned. Remove from oven and cool for 5 – 10 minutes. Carefully remove the crusts from the ramekins and muffin pan. Transfer to cooling rack and cool completely.
Cut the banana into ¼-inch thick.
For the 5½-inch pies, spread a thin layer of filling over the bottom of the crust. Add a layer of banana. If needed, cut a few banana slices to fit. Cover the banana with a good thick layer of custard and smooth the top with the back of a spoon or spatula. Repeat with the 2nd pie crust.
For the 2-inch pies, put a small dollop of filling over the bottom of the crust. Cut a slice banana in half and gently stuff them into the pie. Cover well with a layer of custard and smooth the top. Repeat with the other pies.
Transfer the pies to an airtight container. Chill for at least 5 hours (best overnight).
When ready to serve, in a large mixing bowl fitted with a whisk attachment, add sugar and cold cream. Beat until stiff peak form. Don’t over beat. Decorate the pies with whipped cream and sprinkle with chocolate shaving if using. Serve.