Pour the milk into an ice-cube tray or a 9" x 5" loaf pan. Freeze until solid.
In a small frying pan, sauté the pecans in the oil until lightly browned and fragrant. Transfer to a small bowl, and chill.
Remove the frozen milk from the tray or loaf pan. (You may have to place the container up to its rim in hot water for about 1 minute to loosen the frozen milk.) If you used a loaf pan, use a sharp knife to cut milk into cubes.
Chill a blender container by blending a few regular ice cubes and 3 cups water for 1 minute. Discard the water. Place the maple syrup, vanilla and 2 milk cubes in the container. Blend on high speed until pureed. Add remaining cubes, 2 or 3 at a time, until all are blended. Turn the mixture into a chilled bowl, and stir in the pecans.
If you like soft ice cream, serve at once in chilled bowls. Otherwise, place in the freezer for an hour or two.