Make the pie crust and let it chill in the refrigerator for at least 30 minutes before rolling out. This can be done the day before making the pie. The pie crust recipe makes enough for 2 pies. Freeze half of it for later use.
Preheat oven to 375°F. Roll out the pie dough into a 12-inch circle. Place the pie dough into a 9-inch pie dish. Place the pie dish into the freezer while the oven preheats.
Line the pie crust with crumpled up parchment paper. Crumpling it up helps it to form to the crust. Fill the pie weights or beans and make sure they are evenly distributed. Bake for about 15 minutes or until the edges are starting to brown. Remove the pie from the oven and lift out the parchment paper and and weights. Poke holes with a fork all over the bottom of the pie crust. Return the pie to the oven and bake for another 14-15 minutes. Cool the pie crust completely.
Start the filling by whisking eggs and cornstarch together in a medium sized bowl.
Combine sugar, milk and salt in a medium sized saucepan over medium heat. Whisk occasionally and bring to a boil and then reduce the heat to low. Remove about a ½ cup of the mixture and whisk it into the egg and cornstarch mixture. Whisk continuously so the eggs temper and don't scramble.
Pour the egg mixture into the saucepan and continuously whisk. The pudding with thicken and begin to bubble. Be careful as the bubbles could burst. Whisk and cook for 1 minute and 30 seconds. Remove from the heat and stir in vanilla extract and butter.
Pour about 1 cup of pudding into the bottom of the pie shell. Place banana slices over the top in one single layer, and then pour on the rest of the pudding. Place plastic wrap directly on the surface of the pudding. This helps prevent a skin from forming. Refrigerate the pie for at least 3 hours or overnight.
Make the whipping cream by whipping the heavy whipping cream, sugar and vanilla on high until stiff peaks form. Pipe or spread the whipped cream on top of the pie. Top with the rest of the banana slices.
Toast the flaked coconut by placing them in a frying pan over medium heat. Use a spatula and keep stirring until the coconut flakes have turned a light brown colour. Be care as they can burn very easily. Scatter the coconut flakes over the pie.
Store the pie, covered, in the refrigerator for up to 3 days. Serve cold.