Step 1

In a large bowl, beat 1 cup sugar, milk, peanut butter and oil until well blended. In another bowl, whisk flour, 1/2 cup cocoa and baking powder; gradually beat into peanut butter mixture (batter will be thick). Transfer to a greased 5-qt. slow cooker.

Step 2

In a small bowl, mix the remaining sugar and cocoa. Stir in water. Pour over batter (do not stir).

Step 3

Cook, covered, on high 2 to 2-1/2 hours or until a toothpick inserted in cake portion comes out with moist crumbs. If desired, sprinkle with peanuts. Serve warm.