In a large mixing bowl that is not too deep, combine and whisk together flour and salt. Cut in the chilled lard to the flour mixture using a pastry cutter until the mixture turns into a coarse meal with some large bits.
Combine vinegar and egg in one measuring cup, fill the cup with water until the liquid reaches 1 cup. Gradually pour the liquid into the mixture in the bowl as you stir with a fork. The mixture should cling together when you press them with your fingers. Turn the mixture into a floured board and pat to shape it into one big mass. Divide the dough into three almost equal portions, shape each portion into a disc and wrap it in plastic. Chill in the fridge for at least 2 hours.
After chilling, preheat oven to 375 F. Grease two regular muffin pans. Take one dough portion out of the fridge and roll it into 1/4 inch thickness on a lightly floured board. Using a round cutter that is 4 inches in diameter, cut as many circles as you can. Tip: Dip your cutter in flour before cutting to prevent the dough from sticking to it. Put scraps on top of one another and re-roll again to cut more circles. You should be able to make as much as 12 circles in one portion. Repeat the process with one more portion of the chilled dough. (You will have one portion left of the dough which you can freeze for later use, or make half batch of the filling to make a dozen tart.)
Ease the circles into the muffin holes and press it down to fit the sides. If desired, use the tines of a fork to press little line decorations on the edge on the tart shells. Refrigerate the tart shells while you make the filling.
To make the filling, Beat the eggs on a bowl until the whites and yolk are blended. Beat in the sugar. Add the vanilla, vinegar and melted butter. Stir well. Add the nuts and raisins. Spoon the filling into the tart shells until each is about 1/2-2/3 full. Bake the butter tarts in the preheated oven for 17-20 minutes or until the filling is firm.
Crust recipe from Tenderflake.