Shortbread Tart Shell:

Pulse the flour, sugar, and salt together in the bowl of a food processor. Scatter the pieces of butter over the dry ingredients and pulse until the butter is coarsely cut in. (You’re looking for some pieces the size of oatmeal flakes and some the size of peas.)

Stir egg in a small bowl and add to the flour mixture. Pulse several times in about 10-second intervals until the dough is just beginning to clump.

Turn the dough out onto a work surface and, very lightly and sparingly, knead the dough just to incorporate any dry ingredients that might have escaped mixing.

Press dough into tart pan, working quickly, evenly across the bottom and thicker on the sides. You want to press hard enough that the pieces cling to one another, but not so hard that they lose their crumbly texture. Dock all over with a fork.

Freeze the crust for at least 30 minutes, preferably longer, before baking.

Center a rack in the oven and preheat the oven to 375 degrees F. Butter or spray a piece of aluminum foil (or use nonstick foil) and fit the foil, buttered side down, tightly against the crust.

To fully bake, place the tart pan on a baking sheet and bake the crust for 20 to 25 minutes. Remove from oven. Carefully remove the foil. If the crust has puffed, press it down gently with the back of a spoon. Place back in oven and continue to bake for about 10 minutes longer, until golden brown and firm to the touch in the center of the pan. Transfer the pan to a rack and cool the crust to room temperature, and proceed with the rest of your recipe.

To make ahead:

• For most applications, a fully baked tart shell can be wrapped after cooling and kept for a day or two before using.
• The dough can be wrapped and kept in the refrigerator for up to 5 days or frozen for up to 2 months. Thaw overnight in the fridge before using.
• If dough is to be frozen, it can be patted into the tart pan and frozen, tightly wrapped for up to two months. The flavor is best if baked from frozen rather than thawed first.

Note: this is just slightly skimpy for a 10″ pan, but with careful patting, it works just fine.

For the Banoffee Pie:

Carefully spoon the Dulce de Leche over the pastry and smooth the top. Add the peeled and sliced bananas.

Mix together the powdered sugar, cornstarch, and instant coffee. Whip the cream until soupy, add the sugar mixture, and continue to beat until stiff peaks form.

Dollop the whipped cream over the bananas and smooth or finish as you’d like. Sprinkle with a few pinches of coffee.

Refrigerate until ready to serve.