Heat oven to 325°.
Lay the pecan halves on a rimmed cookie sheet. Bake for 15 minutes, tossing the pan halfway. Remove from oven when nuts are fragrant and about two shades darker than they started.
Transfer pecans to a food processor. Process for 5 minutes, until smooth and creamy.
Stir in maple syrup, vanilla, and salt.
Store in an airtight container in the refrigerator up to one month.