Combine butter, brown sugar, water, molasses, allspice, cinnamon, cloves, ginger, and black pepper in a saucepan. Simmer over medium heat, then remove from heat and allow to cool. Once warm, stir in vanilla extract and transfer to a mixing bowl. Cover and let stand at room temperature for at least 8 hours.

Stir raisins, dates, pecans, and candied fruit into the cooled mixture. Whisk salt, baking soda, and flour together, then stir into the fruit mixture until no dry lumps remain. Refrigerate dough for 3 to 4 hours or until firm.

Preheat the oven to 350°F (175°C).

Form the dough into golf-ball-sized balls and place on ungreased baking sheets, spacing them 1 1/2 inches apart. Flatten each ball to 1/4-inch thickness with your palm.