For the dough, knead the flour, butter, salt, egg and sugar into a smooth dough. Wrap the dough in plastic and chill for 30 minutes. Grease a tart tin with butter. Preheat the oven to 200°C (approximately 400°F). Roll out the dough on a floured surface. Line the tart tin with the dough, forming an edge. Pierce the dough several times with fork. Line the dough with parchment paper and cover with dried beans. Bake for 20-25 minutes, until golden brown. Remove the parchment paper with the beans. Let the crust cool.
For the filling, bring the cream, sugar, butter and liqueur to a boil. Simmer over low heat for 20-30 minutes, stirring contantly, until the mixture is light brown and thick. Remove from the heat and let cool slighlty. Spread the caramel cream on the crust. Lightly roast the pecans in a dry frying pan, remove from the heat and cool slightly. Spread the pecans on the cream. Chill for about 1 hour. Cut into pieces and serve.