1. Preheat oven to 350°. Spray a 13- x 9-inch baking pan with cooking spray.
2. In a small bowl, whisk together flour, baking soda, and cinnamon. In a large bowl, beat brown sugar and peanut butter until well combined. Beat in eggs, oil, and vanilla. Stir in flour mixture. Add barley flakes (or rolled oats), cranberries, peanuts, and 3/4 cup chocolate chips, stirring to combine.
3. Spread evenly in prepared pan. Bake 20-25 minutes, until lightly browned and firm to the touch. Cool completely in pan on wire rack.
4. In a small bowl set in a pan of simmering water, melt remaining 1/4 cup chocolate chips, stirring until smooth. With fork, drizzle chocolate over bars; refrigerate until set. Cut into 24 bars.