Step 1: Prepare the Perfect No-Bake Crust

1. Crush the Biscuits: Place the Digestive biscuits into a food processor and pulse until they resemble fine breadcrumbs or sand. If you don’t have a food processor, place the biscuits in a large, sealed ziplock bag. Lay the bag flat and use a rolling pin or a heavy-bottomed pan to crush them until you achieve a fine, even crumb. Ensure there are no large lumps left.
2. Combine with Butter: Transfer the biscuit crumbs to a medium-sized mixing bowl. Pour the melted unsalted butter over the crumbs. Using a spatula or fork, mix thoroughly until all the crumbs are evenly coated in butter. The mixture should feel like wet sand.
3. Press into the Pan: Tip the buttery crumb mixture into a 9-inch (23cm) loose-bottomed tart pan or a springform pan. First, use the back of a spoon or the bottom of a measuring cup to press the crumbs firmly and evenly across the base. Then, work the crumbs up the sides of the pan, pressing firmly to create a solid, even wall. A flat-bottomed glass can be very helpful for this.
4. Chill the Crust: Place the pan in the refrigerator for at least 30 minutes (or in the freezer for 15 minutes if you’re short on time). This step is crucial. Chilling the crust solidifies the butter, creating a firm base that won’t crumble when you add the filling or slice the pie.

Step 2: Create the Luscious Caramel Layer

1. Spread the Caramel: Once the crust is chilled and firm, retrieve it from the refrigerator. Open your can of dulce de leche or caramel. Spoon the entire contents onto the center of the biscuit base.
2. Even it Out: Using an offset spatula or the back of a spoon, gently spread the caramel in a thick, even layer, covering the entire base. Be careful not to disturb the biscuit crust as you spread.

Step 3: Add the Fresh Banana Layer

1. Prepare the Bananas: Peel and slice your ripe bananas into rounds about 1/4-inch (1/2 cm) thick. If you’re concerned about them browning, place the slices in a bowl and gently toss them with the teaspoon of lemon juice. This is especially recommended if you’re not serving the pie immediately.
2. Arrange the Slices: Arrange the banana slices in a single, slightly overlapping layer on top of the caramel. You can create a decorative concentric circle pattern or simply ensure the caramel is completely covered. Use enough bananas to create a generous layer.

Step 4: Whip Up the Cloud-Like Cream Topping

1. Whip the Cream: In a large, chilled mixing bowl, pour in the very cold heavy whipping cream. Using an electric hand mixer or a stand mixer with a whisk attachment, begin whipping on medium speed.
2. Add Sugar and Vanilla: Once the cream starts to thicken and form soft peaks (when you lift the beaters, a peak forms but flops over), add the icing sugar and vanilla extract.
3. Whip to Stiff Peaks: Continue whipping on medium-high speed until the cream is thick, voluminous, and forms stiff peaks. This means when you lift the beaters, the peak holds its shape without collapsing. Be careful not to over-whip, or the cream will start to turn grainy and buttery.
4. Top the Pie: Spoon the whipped cream over the banana layer. You can either spread it evenly with a spatula for a smooth finish or create beautiful, rustic swirls and peaks with the back of a spoon for a more dramatic effect.

Step 5: The Final Flourish and Chilling

1. Garnish: Using a vegetable peeler or a fine grater, shave curls of dark chocolate over the top of the cream. Alternatively, you can use a small sieve to dust the top with a light, even layer of cocoa powder.
2. Chill Before Serving: For the best results, return the assembled pie to the refrigerator to chill for at least 1-2 hours before serving. This allows the flavors to meld together and ensures the pie is firm enough to slice cleanly.