Preheat the oven to 350 degrees. Coat a 9- by 13-inch baking dish with nonstick cooking spray. In a small saucepan, melt the chocolate chips in the milk over low heat; set aside.

In a large bowl, beat the butter and sugar until creamy. Add the eggs one at a time, mixing well after each addition. Add the chocolate mixture; mix until thoroughly combined. Add the whole-wheat and all-purpose flours, the baking soda, and coffee; continue beating until well combined.

Pour the batter into the baking dish and bake for 22 to 25 minutes, or until a toothpick inserted in the center comes out clean. Allow to cool completely, then cut into squares and serve.

This recipe yields 24 servings. Serving size: 1 square.

Exchanges Per Serving: 1 1/2 Carbohydrate, 1/2 Fat.

Nutrition Facts: Calories 119; Calories from Fat 34; Fat 4g; Saturated Fat 2g; Cholesterol 29mg; Sodium 115mg; Carbohydrates 20g; Dietary Fiber 1g; Sugars 12g; Protein 2g.