Stockholm Chocolate Festival Cake

The Stockholm Chocolate Festival is happening this coming weekend. On their web page I found the recipe for the "festival dessert". The recipe is intended to be made into individual servings and is dimensioned for a much larger scale than I want to make.
I scaled the recipe down a bit and adapted it to make one 9" cake.

Chocolate cake base:

• 150 grams soft butter
• 130 grams sugar
• 150 grams melted chocolate, 70%
• 2 eggs
• 40 grams flour

1. Mix well (in the order that the ingredients are listed) to a smooth batter.
2. Pour into a greased spring-form pan (9").
3. Bake for 10 minutes in a 200C oven. Let it cool off.

Raspberry truffle:

• 120 grams raspberry puree
• 60 grams unsalted butter
• 150 grams sugar
• 45 grams double cream

• 135 grams milk chocolate
• 135 grams dark chocolate (70%)

1. Chop both chocolates and place in a bowl.
2. Bring the other ingredients to a boil. Pour this mixture over the chocolate.
3. Mix to a smooth mixture.
4. When the mixture is 30C, pour over the chocolate cake base and place everything in the freezer.

Milk chocolate mousse:

• 100 grams double cream
• 210 grams milk chocolate

Bring the cream to a boil and pour over the chocolate. Stir until the chocolate melts and the mixture is smooth.

• 70 grams sugar
• 21 grams water
• 1 egg + 1 egg yolk
• 310 grams lightly whipped cream
• 1 sheet of gelatin, soaked in water

Let the sugar and water boil to a syrup until it reaches a temperature of 121C. Pour this over the egg and egg yolk while constantly whisking. Keep whipping the egg mixture coldly.

Fold the chocolate mixture, the egg mixture, the gelatin, and the lightly whipped cream together.
Pour the mousse into the spring form pan and make the surface of the cake smooth. Put it back into the freezer.

Take out of freezer a few hours before serving to give it time to defrost properly.

Decoration
Decorate the cake as you see fit. I took a cake decorating course (Wilton Course 1) this past weekend, so I wanted to make use of my new skills, so I made some buttercream and piped the roses and leafs. (I made lots of roses... I should have taken a picture of my plate full of roses. While it was tricky at first, it is actually rather easy to pipe roses once you get the hang of it.)