Preheat the oven to 350ºF (180ºC). In a medium-size saucepan, combine the pecans, butter, brown sugar and maple syrup over medium heat. Bring to a simmer and let the mixture bubble gently for 2 minutes. Remove the pan from the heat and stir in the heavy cream, cinnamon and salt. Return the pan to the heat and let the mixture bubble gently on low heat for 2 more minutes. Stir in the vanilla and let the mixture cool to lukewarm.