Line a rimmed baking sheet with foil and top with a wire rack. Lay the bacon in a single layer on the wire rack (it can touch slightly but not overlap).
In a small bowl, stir together the brown sugar, maple syrup, and Dijon mustard. Use a pastry brush to brush the half the brown sugar mixture over the bacon.
Bake the bacon for 20–25 minutes, or until the bacon is mostly cooked through.
Remove from the oven and flip the bacon onto the other side. Brush the bacon with the remaining brown sugar mixture. and sprinkle the chopped pecans over the top, pressing gently with a spatula to adhere if necessary.
Return to the oven and cook until the bacon is very crisp, about 5–10 more minutes.
Remove from the oven and let cool slightly. Serve immediately.
You can make this with regular cut bacon instead of thick cut. You may need to reduce the cooking time. The recipe was updated in April 2022 with new instructions for brushing the bacon with the remaining brown sugar mixture after the initial cook time (instead of before).