Preheat the oven to 350 degrees. In a food processor, pulse the flour, 4 tbsp. sugar and the salt. Add the butter and pulse until the butter is evenly incorporated. Press mixture firmly into a 9-inch pie dish. Bake the crust until golden, 20 to 25 minutes. Let cool completely.
In a medium bowl, mix the pudding and the espresso powder. In another medium bowl using an electric mixer, beat the cream, vanilla and the remaining 1 tbsp. sugar until stiff peaks form.
Line the bottom of the piecrust with three-quarters of the banana slices. Sprinkle with 1/2 cup toffee bits. Spoon in the pudding mixture, smoothing the top. Top with the remaining banana slices, whipped cream and more toffee bits.