Preheat your oven to 325°F.
Line a 9x9-inch baking pan with parchment paper, leaving a little parchment hanging over the sides so the brownies are easy to lift out once they're cooled.
In a large mixing bowl, whisk together the brewed decaf coffee, melted salted butter, and egg until combined.
Add the brownie mix and stir just until everything comes together.
Fold in the chopped pecans.
Pour the brownie batter into your prepared 9x9-inch baking pan and spread it into an even layer.
Bake at 325°F for 40–45 minutes, or until the brownies are baked through according to your desired texture.
Remove from the oven and allow the brownies to cool completely before frosting.
While the brownies cool, make your frosting. Add the room-temperature salted butter, maple syrup, maple extract, cinnamon, and salt to a large mixing bowl.
Using a hand mixer or stand mixer, beat until smooth and combined.
Gradually add the powdered sugar ½ cup at a time, beating between each addition, until the frosting reaches your desired sweetness and consistency.
Once the brownies have cooled completely, spread the salted maple frosting evenly over the top.
Finish with a light dusting of ground cinnamon, slice into squares, and enjoy!