Serves 24.
The 24 servings are pretty big -- they're dessert size, not snack size. But keep this in mind: The cakes are frosted and coated with peanuts on every surface but the bottom. If you cut them smaller you'll need more frosting and peanuts to cover all those sides.
Cake:
1 c. sugar
1/2 c. (1 stick) butter, softened
3 eggs
1 tsp. vanilla
2 c. flour
2 tsp. baking powder
1/2 c. milk
Frosting:
6 tbsp. (3/4 stick) butter, softened
3 c. powdered sugar
41/2 tbsp. milk
11/2 tsp. vanilla
1 (10-oz.) container blanched salted peanuts (about 21/2 c.)
Prepare the cake: Preheat the oven to 350 degrees. Grease and flour a 9- by 13-inch pan. In the large bowl of an electric mixer, cream the sugar and the 1/2 cup of softened butter until the mixture is uniform and fluffy. Add the eggs, one at a time, beating well and scraping the bowl after each. Beat in the vanilla.
Sift together the flour and baking powder and beat into the batter in thirds, alternating with the milk. Pour and scrape into the prepared pan, and level into the corners. Bake 18 to 20 minutes, or until a toothpick inserted in the center comes out clean. Cool completely and cut into serving pieces.
Prepare the frosting: In the small bowl of an electric mixer, cream the butter. Gradually add the powdered sugar, alternating with additions of the milk, and beating well after each. Beat in the vanilla, and more milk or powdered sugar as needed to make a soft frosting.
Chop the peanuts briefly in a food processor until they are coarse pieces, and pour them into a shallow bowl.
For the frosting and coating with peanuts, it's not a bad idea to wear kitchen gloves or small plastic bags on your hands. Have a large baking sheet or several plates handy. Using a spatula, frost top and all four sides of a piece of cake, then roll it in the peanuts to coat top and sides. Brush away any peanuts that cling to the bottom, then set the finished piece on the baking sheet. Repeat with remaining pieces and allow to air-dry several hours. Store the sheet loosely covered. If the cakes are stored in the refrigerator they will be less messy when eaten out of hand.
