• Heat oven to 350F. Grease the bottom and sides of two 8" round cake pans.
• In a large mixing bowl mix Betty Crocker Chocolate Fudge Cake Mix with water, oil, eggs and chopped Toblerone bar. Use a whisk to combine until a smooth batter forms. Pour into the prepared pans.
• Bake for 25-30 minutes, or until a toothpick inserted in the centre comes out clean. Cool 10 minutes before remove the cakes from their pans and cool on a rack completely before frosting.

Chocolate Icing

• In a stand mixer fitted with the paddle attachment, beat together the butter and powdered sugar on low until well-blended. Add the Nutella, vanilla extract and cream then increase the speed to medium. Beat for two minutes until a smooth icing forms.

Assembly

• Place one of the chocolate cake rounds in the centre of a cake stand.
• Using a palette knife add a thin layer of buttercream icing. Evenly sprinkle 100g of chopped Toblerone. Gently place the other chocolate cake round on top, creating a 2-layer cake.
• Using a palette knife add half of the remaining buttercream icing to the sides and top of the cake in a very thin layer called a "crumb layer." Smooth over the surfaces so they are even. Place the cake in your fridge to chill for at least 30 minutes.
• Using a palette knife add the chocolate icing to the sides and top of the cake. Smooth over the surfaces so they are even.
• Fill the remaining buttercream icing into a piping bag. Decorate the edges of the cake with the buttercream using your favourite decorative tip. Make sure to leave a space between each buttercream dollop to place a piece of the small Toblerone chocolate bar. The edges of the cake should alternative with buttercream and Toblerone pieces.
• Take the remaining chopped Toblerone bars and sprinkle them into the centre of the cake.
• Slice and serve.