Prepare the Biscuit Base: Blend the digestive biscuits in a food processor until fine, then mix with melted butter and press firmly into a tart pan. Refrigerate for 1 hour.

Make the Toffee Filling: Cook sweetened condensed milk in a saucepan over medium heat, stirring for 5-7 minutes until thickened to golden brown, then pour over the biscuit base.

Layer the Bananas: Slice the medium bananas and arrange them evenly over the cooled toffee layer.

Whip the Cream Topping: Mix heavy cream, powdered sugar, and vanilla extract in a bowl and whip until soft peaks form.

Assemble and Decorate: Spread whipped cream over the bananas and optionally drizzle with dark chocolate or dust with cocoa powder.

Chill and Serve: Refrigerate for at least 2 hours before serving.