Prehead oven to 160ºC . Mix together the butter and cream cheese in a small bowl or food processor. Add the flour and blend thoroughly. Divide and shape into 30 balls. Wrap all 30 balls together in plastic wrap and chill slightly. Place each ball in a tiny ungreased fluted tart pan or muffin cup. Line the pans by pressing the dough with your fingertips against the bottoms and sides.
For the filling, place half the pecans in the dough-lined pan. Beat together the egg, sugar, butter, vanilla, and salt until all lumps are gone. Pour the egg mixture onto the pecan topped dough.
Dot with the remaining pecans. Bake for 25 minutes or until the filling is set. Cool 5 minutes on a rack and remove from the pans before they are cool, as the caramel will set. These tiny tarts freeze easily.