Start by making your toffee sauce. In a saucepan, combine the superfine sugar and whole milk over medium heat. Stir continuously until the sugar dissolves. Bring the mixture to a gentle simmer and cook for about 2-3 minutes. Then, remove from heat and let it cool slightly. The toffee sauce should be thick and glossy.

While your toffee cools, it’s time to whip the cream. In a mixing bowl, pour the heavy cream and add the optional vanilla extract if you're using it. Using a hand mixer or whisk, whip the cream until soft peaks form. Make sure not to over-whip it; you want it to be lovely and fluffy.

Take your pre-made pie crust and layer sliced bananas at the bottom. Pour the cooled toffee sauce over the bananas. Spread it evenly to ensure every bite has that sweet flavor. Next, carefully spoon the whipped cream over the toffee. Use a spatula to create a smooth top.

The last step before serving involves adding chocolate. Grate or shave dark chocolate over the whipped cream layer. This not only adds a bitter contrast but also enhances the visual appeal of your pie with its rich color.

Refrigerate the pie for at least 1 hour to let the layers set. Serve chilled, and for added pizzazz, top with additional banana slices or a drizzle of honey.