Preheat the oven to 350 degrees F, and line a sheet pan with aluminum foil.
Place the pecans on the sheet pan and toast in the oven until fragrant, approximately 10 minutes. Gently flip every 3 to 4 minutes to toast evenly on both sides.
While the pecans are toasting, prepare the candy coating. Microwave the butter in a large microwave-safe bowl until melted, about 20 seconds. Stir in the maple syrup, brown sugar, cinnamon, salt, and cayenne, if using.
Remove the pecans from the oven and pour them into the mixture. Be careful as it might splutter. Stir until the pecans are evenly coated, then pour back onto the sheet pan and spread in an even layer.
Bake for additional 10 minutes, stirring after every 3-4 minutes. Remove from the oven and allow to cool and firm up on the sheet pan.
Once cool, break the nuts apart. Store in an airtight container at room temperature. They're best enjoyed within 1-2 weeks (the spices will be most pronounced), but will keep in an airtight container in the pantry for up to 1 month. You can also store them in the freezer for up to 6 months using an airtight container or resealable freezer bag.
You can use either light or dark brown sugar. Dark brown sugar results in a deeper flavor, but both taste great.