Step 1 Heat the oven to 325 degrees.
Step 2 In a food processor, blender or nut grinder, grind the pecans until they have the consistency of fine crumbs.
Step 3In a medium bowl, whisk together the oil, maple syrup and cinnamon, then add the ground pecans and mix well.
Step 4Grease an 11-inch tart pan with olive oil. Place the pan on a large cookie sheet.
Step 5Press the crust mixture evenly into the pie or tart pan. (Line the mixture with a layer of plastic wrap so it does not stick to your fingers as you form the crust.)
Step 6Put pie weights over the crust to prevent it from puffing up.
Step 7Bake the crust (with the pan on the cookie sheet) until the sides are set, about 20 minutes. Remove the weights and continue to bake until the crust is set (similar to a graham cracker crust) and no longer moist, an additional 10 to 15 minutes; the crust will continue to harden as it cools. Remove it from the oven and set aside to cool while you make the tart filling.