1/2 cup creamy peanut butter 
6 tablespoons butter, cubed 
1 cup water 
2 cups all-purpose flour 
1-1/2 cups sugar 
1/2 cup buttermilk 
1/4 cup unsweetened applesauce 
2 large eggs, lightly beaten 
1-1/4 teaspoons baking powder 
1 teaspoon vanilla extract 
1/2 teaspoon salt 
1/4 teaspoon baking soda 
FROSTING 
1/4 cup butter, cubed 
1/4 cup creamy peanut butter 
2 tablespoons fat-free milk 
1-3/4 cups confectioners' sugar 
1 teaspoon vanilla extract
1. In a large saucepan, bring peanut butter, butter and water just to a boil. Immediately remove from the heat; stir in the flour, sugar, buttermilk, applesauce, eggs, baking powder, vanilla, salt and baking soda until smooth. 
2. Pour into a 15x10x1-in. baking pan coated with cooking spray. Bake at 375° for 15 to 20 minutes or until golden brown and a toothpick inserted in the center comes out clean. Cool on a wire rack for 20 minutes. 
3. In a small saucepan, melt butter and peanut butter over medium heat; add milk. Bring to a boil. Remove from the heat. Gradually whisk in confectioners' sugar and vanilla until smooth. Spread over warm cake. Cool completely on a wire rack. Refrigerate leftovers.
TOTAL TIME: Prep: 20 min. Bake: 15 min. + cooling 
YIELD: 24 servings. 
Nutrition Facts
1 piece: 220 calories, 9g fat (4g saturated fat), 30mg cholesterol, 166mg sodium, 31g carbohydrate (22g sugars, 1g fiber), 4g protein. Diabetic Exchanges: 2 starch, 1-1/2 fat.