Prepare Toffee Filling

1. Remove the labels from sweetened, condensed milk cans and place the unopened cans in a saucepan of boiling water, making sure they are fully submerged
2. Lower the heat to keep the water simmering and cook for 3 hours. The cans must be completely covered with water, so check every so often and add additional water if evaporated.Turn the cans over in the water occasionally
3. After 3 hours, remove the cans from the boiling water and set aside to cool. These can be left on the shelf at room temperature for months, so this step can be done in advance

Make & Bake Crust

1. Preheat oven to 350º
2. In a standing mixer fitted with a paddle attachment, combine flour, softened butter and pinch of salt. Mix until it resembles fine breadcrumbs
3. Add cold water, 1 tablespoon at a time, until the dough binds into a ball
4. Transfer to a floured surface and gather the dough with your hands to remove any air pockets
5. Roll into a round, about ¼" thick (big enough to cover a 9" pie plate)
6. Grease a 9" pie tin with butter and coat with flour, shaking out the excess. Fit the pie tin with the pastry, pressing it in. Cut the excess dough from the rim of the pie plate
7. Line the pastry with foil or parchment, and fill with pie weights, dried rice or dried beans (to weight the crust while baking)
8. Bake 10-15 minutes. Remove the foil or parchment & weights and bake an additional 10-15 minutes, or until golden brown 
9. Remove the crust from the oven and leave to cool in the pan
10. Once the pastry has cooled, open the sweetned, condensed milk cans and spread the contents in the crust
11. Refrigerate at least 2 hours, or overnight to set the toffee filling

Make Whipped Cream & Finish

1. Lay sliced bananas evenly over the toffee filling
2. Whisk the heavy cream until it forms soft peaks
3. Add the sugar and 1 tsp of the instant coffee powder
4. Whip cream to medium-stiff peaks
5. Spread the cream mixture over the sliced bananas
6. Sprinkle with a pinch of instant coffee powder to finish