Preheat oven to 150C (300F).
Spread pecans out over baking paper-lined baking trays. Place the pecans in the oven and toast for 8-10 minutes only. Cool briefly.
Combine melted butter, maple syrup, vanilla and cinnamon in a large bowl and mix well. Add pecans and stir to coat evenly. Spread nuts out on the lined baking sheets evenly and return to oven for 20-25 minutes, taking care to check to make sure they aren't burning.
Remove from oven, sprinkle with salt while still hot and sticky, then spread out on counter or cake rack to cool completely.
Store in an airtight jar.