British Treacle Tart
Combine flour, salt and confectioner’s sugar in a large bowl. Using tips of fingers, rub butter into flour until it looks mostly like wet sand. Make a well in the middle, and pour in the egg. Gradually work the egg into the flour until a moist dough forms, using the heel of your hand to distribute any remaining large pieces of butter. Shape into a 5-inch disk and cover with plastic wrap. Refrigerate for 1 hour. This can be done in a food processor.
Increase the temperature to 350 F
Pour the mixture into the prepared tart case.