Butter a 6-quart slow cooker with 2 tablespoons butter. Sprinkle ½ cup brown sugar evenly over the bottom. Top with 4 tablespoons butter, the pecans and ⅔ cup water. (If you plan to serve the dish immediately after cooking rather than keeping it warm in the slow cooker, reduce the water to ⅓ cup.)
In a medium bowl combine the remaining cup of brown sugar, coarse salt and ground cinnamon. Cut each biscuit into quarters and roll it into a ball. Coat each ball in butter and then brown sugar mixture and place in slow cooker in an even single layer. Cover the slow cooker and cook on low for 1 ½ to 2 hours, or until dough is cooked through in the center. Keep warm up to five hours.
To serve, uncover the slow cooker and place an inverted serving platter the same size or larger over top. Using kitchen towels if slow cooker is still warm, press the platter over the bowl of the cooker and carefully flip it over to release the monkey bread.