2 cups all-purpose flour 
2 cups sugar 
1 teaspoon baking soda 
1/2 teaspoon salt 
1 cup water 
3/4 cup butter, cubed 
1/2 cup chunky peanut butter 
1/4 cup canola oil 
2 large eggs, room temperature 
1/2 cup buttermilk 
1 teaspoon vanilla extract 
GLAZE:
2/3 cup sugar 
1/3 cup evaporated milk 
1 tablespoon butter 
1/3 cup chunky peanut butter 
1/3 cup miniature marshmallows 
1/2 teaspoon vanilla extract
1. Preheat oven to 350°. Grease a 15x10x1-in. baking pan. 2. In a large bowl, whisk flour, sugar, baking soda and salt. In a small saucepan, combine water and butter; bring just to a boil. Stir in peanut butter and oil until blended. Stir into flour mixture. In a small bowl, whisk eggs, buttermilk and vanilla until blended; add to flour mixture, whisking constantly. 
3. Transfer to prepared pan. Bake until a toothpick inserted in center comes out clean, 20 to 25 minutes. 
4. Meanwhile, for glaze, combine sugar, milk and butter in a saucepan. Bring to a boil, stirring constantly; cook and stir 2 minutes. Remove from heat; stir in peanut butter, marshmallows and vanilla until blended. Spoon over warm cake, spreading evenly. Cool on a wire rack.
TOTAL TIME: Prep: 15 min. Bake: 20 min. 
YIELD: 24 servings. 
Nutrition Facts
1 piece: 266 calories, 14g fat (5g saturated fat), 36mg cholesterol, 222mg sodium, 33g carbohydrate (23g sugars, 1g fiber), 4g protein.