Heat oven to 350 degrees, then butter a 13 x 9 inch pan and set aside.
Cream the softened butter, sugar and salt in a large bowl with a wooden spoon. Stir in the oats (you can use either Quick or Old Fashioned oats), then stir in the flour a third at a time, rubbing in the last bit of it by hand to make coarse crumbs. Sprinkle on the water and rub briefly. Press the dough into the pan, spreading it evenly into the bottom and very slightly up the sides. Chill the pan for 15 minutes. Then bake the pastry on the center oven rack for 15 minutes. Transfer the crust, in the pan, to a wire rack to cool thoroughly.
Heat the oven again to 350 degrees. Combine the maple syrup, brown sugar, cream and butter in a med size saucepan. Bring the mixture to a full boil. Boil for 30 seconds, then remove the pan from the heat and stir in the vanilla and pecans.
Immediately pour the maple pecan filling over the crust, spreading it evenly over with a spoon. Bake the bars on the center oven rack for 15 minutes. Transfer the bars in the pan, to a wire rack to cool thoroughly. Cover and refrigerate the bars for 1 to 2 hours before slicing.
Cooking time does not include cooling time.