In a large bowl, combine the pecans, graham cracker crumbs, brown sugar, salt, butter, maple syrup, rum extract and corn syrup until well mixed and slightly crumbly. Use your clean hands to make sure it's well combined.
Use a cookie scoop to scoop out balls of the pecan mixture. Gently roll the balls until they are smooth. Be careful to not squeeze them too hard or they may fall apart.
Lay out the balls on a cutting board or a parchment-lined baking sheet. Place the balls in the freezer for 1 hour.
Melt the chopped chocolate in a small microwave-safe bowl until smooth.
Drop the pecan balls, one at a time, into the chocolate and then roll them around until they are evenly coated. Set the balls back on the parchment paper and top with a few pecan pieces before the chocolate sets.
Let the pecan balls sit until the chocolate fully sets. You can put them in the freeze for a few minutes (5 to 10 minute should do the trick) to help them set faster. Serve at room temperature.