Falling in love with baking: Blueberry Mousse Cake

It's my baby Blaze's birthday yesterday! Blaze is turning 6 years young and she loves blueberries. My parents have a blueberry tree in their backyard and Blaze has got caught many times eating the fresh blueberries off the tree! Since it's her birthday, I decided to bake her a blueberry mousse cake. Well, it's for all of us actually, who doesn't love cake?

Blueberry Mousse Cake

Recipe adapted from here and here

Ingredients:

(for sponge cake)

1 cup plus 1 tbsp cake flour
1 tsp baking powder
6 eggs, separated (room temperature)
1/2 tsp cream of tartar
1/8 tsp salt
1 tsp pure vanilla extract
1/2 cup granulated sugar
1/2 cup water
1/3 cup vegetable oil

(for blueberry mousse)

1 cup blueberry puree

2 tbs sugar
1 packet gelatine powder
1/4 cup water
1/2 cup heavy cream

(for stablized whipped cream)
1 cup heavy whipping cream
2 tbsp Confectioner's sugar
1/2 tsp vanilla extract
1 tsp gelatine powder
4 tsp water

(for raspberry whipped cream)
Reserve about 1/2-1 cup of stablized whipped cream)
2 tbsp of raspbery puree

Directions:

1. Preheat oven to 340F degrees.
2. Line a 9" x 13" pan with parchment paper, set aside.
3. Sift the flour and baking powder together 3 times. Set aside.
4. In a large bowl, combine the egg yolks, salt, vanilla extract, and 4 tablespoons of the sugar (reserve the rest for later). Whisk for several minutes, until the mixture turns pale yellow and thick ribbons fall from the whisk.
5. Stir in the water and the oil, and whisk well between each addition. Fold in the flour mixture and whisk until well blended, but don't overmix.
6. In another large, clean bowl, combine the egg whites, cream of tartar and reserved sugar, and beat with a clean whisk until stiff. You may use an electric whisk or a stand mixer with the whisk attachment; make sure neither the bowl nor the whisk have any trace of fat, or the eggs will not rise and cake will be of flat variety and not of sponge decent.
7. Fold a third of the beaten egg whites into the batter and mix gently until blended. Fold in the rest of the egg whites, gently lifting the batter up and over the egg whites with a rubber spatula until just blended.
8. Pour the batter into the baking pan. Bake until set and golden brown (about 35-40 minutes)
9. Invert the baking pan onto a cooling rack so the cake will not collapse, and let cool completely.

While waiting for the cake to cool, prepare the blueberry mousse and whipped cream:

(for blueberry mousse)
1. In a blender, puree the blueberries and then add sugar. Continue blending for a few seconds to make sure that all the sugar dissolves.
2. Sprinkle the gelatine powder over the water and let it bloom for about 5 minutes. Heat the gelatine for 15 seconds at 50% power in the microwave. Once the gelatine is melted, pour it slowly to the puree while stirring it continuously.
3. Whip the heavy cream to soft peaks. Fold the whipped cream into the puree.

(for stablized whipped cream)
1. Put the cold water in a small saucepan. Sprinkle the gelatin over the surface of the water and let stand for 5 minutes (do not stir). Place the saucepan over low heat and stir constantly with a wooden spoon just until the gelatin dissolves. Remove the saucepan from the heat and cool to room temperature.
2.In a mixing bowl, combine the whipping cream, sugar, and vanilla and beat until slightly thickened. Then, while beating slowly, gradually pour the gelatin into the whipped cream mixture. Then whip the mixture at high speed until stiff.

(for raspberry whipped cream)
1. Reserve about 1/2-1 cup of stablized whipped cream and mix with 2 tbsp of raspberry puree

To assemble cake: