Ingredients (makes 1 Cake)

• 2 1/4 cups Plain flour
• 1 1/2 cups Sugar
• 1/2 cup Peanut butter
• 1 1/4 cups Milk
• 3 1/2 teaspoons Baking powder
• 1 teaspoon Salt
• 1 teaspoon Vanilla
• 3 Eggs
• 3 tablespoons Unsweetened cocoa powder
• 1/8th teaspoon Bicarbonate Soda
• 1/4 cup Hot fudge topping
• 3 cups Icing sugar
• 1/3 cup Butter softened
• 1 1/2 teaspoons Vanilla essence
• 1/4 cup Milk
• 1/4 cup Peanut butter
• 1/2 cup Finely chopped peanuts

Method

1. Heat oven to 180 degrees celcius. Grease bottom & sides of round cake pan.
2. Heat oven to 350°F. Grease bottom and sides of cake tin. In large bowl, beat flour, sugar, 1/2 cup peanut butter, 1 1/4 cups milk, baking powder, salt, vanilla and eggs with electric mixer on low speed for 30 seconds, scraping bowl constantly. Beat on high speed 3 minutes, scraping bowl occasionally.
3. two-thirds of batter (about 3 cups) into tin.. Stir cocoa and bicarb soda into remaining batter. Drop chocolate batter by generous tablespoonfuls randomly in mounds onto peanut butter batter. Pull knife through batters in continuous motion for marbled design. Turn pan one-fourth turn; repeat marbling.
4. Bake cake for 45 minutes or until skewer comes out clean when inserted or cake springs back when touched lightly in centre. Cool cake on cooling rack.
5. In medium bowl, mix icing sugar and butter. Stir in vanilla, 1/4 cup milk and 1/4 cup peanut butter; beat until smooth and spreadable. Spread over frosting. Drop hot fudge topping by teaspoonfuls randomly over top; pull knife through frosting in cross cross shape in continuous motion for marbled design. Decorate with chopped nuts.

Notes

I used crunchy peanut butter however, any will do. I used the crushed nuts that often come with a sundae, just not sure what they're called however, can be found in supermarket.