Spread pecans on a large baking sheet. Transfer to oven and roast for 10 minutes.
Remove from oven and place pecans, cacao, vanilla and salt in a food processor. Process for 2 minutes, or until smooth. Towards the beginning, you may need to stop to scrape down the sides.
Remove blade or transfer to a mixing bowl. Stir in maple syrup, if desired.
Serve immediately. Store refrigerated in a sealed container.
Notes
This recipe is rich and delicious without the maple syrup, though not as sweet.