Preheat oven (or toaster oven) to 350 degrees F. Line a baking sheet with parchment paper.
In a microwave-safe bowl or measuring cup, add butter, cinnamon, and maple syrup. Microwave on high heat for 1-2 minutes, until butter is melted and mixture is bubbly.
Add the pecans to the butter and syrup mixture, and stir to coat well. Spread pecans in a single layer on the baking sheet, and sprinkle with a pinch of kosher salt if desired. Bake in preheated oven for 5 minutes. (These nuts can burn very quickly, so do not over bake! As soon as they start looking darker brown, take them out.)
Allow to cool on the parchment paper before enjoying or storing.