To make Noriko’s Sponge Cake:
Preheat the oven to 350 degrees Fahrenheit (170 to 180 degrees Celsius). Line a 7 (18cm) or 8-inch circular cake pan with parchment paper, or grease the cake pan with butter, then lightly coat the pan with flour. Add the sugar to the egg whites, and beat the egg whites until they are stiff and glossy. Add the egg yolks to the egg white mixture, and gently whisk until the yolks are incorporated. Add the milk, vanilla extract, and flour (in that order) to the batter and gently fold them into the batter with a spatula. Fold in the melted butter until it is well combined. Pour the cake batter into the prepared cake pan, and get rid of any air bubbles in the batter by dropping the pan on a counter once or twice. Bake the cake for 25 to 30 minutes. The cake is done when it is golden brown and springs back when pressed lightly. Let the cake cool completely on a wire rack. Run a blade around the inside of the pan to loosen the cake, and remove.
To make the Stabilized Whipped Cream Frosting:
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. 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.
To make the Simple Syrup:
In a medium saucepan combine the sugar and water. Bring the water to a boil, stirring, until sugar has dissolved. Remove from the heat and allow to cool.
To assemble the cake:
Reserve 6 to 1o strawberries for decorating the cake. Slice the remaining strawberries into thin slices (about 4 slices per strawberry). Slice the sponge cake horizontally into 2 layers. Place one sponge layer cut-side up on a cake board or serving plate and lightly crush the surface with the simple syrup. Spread a thin layer of whipped cream over the cake layer and arrange the strawberry slices over the surface. Spread an additional layer of whipped cream over the strawberries. Brush the cut-side of the second layer with the simple syrup and place it over the first layer. Frost the sides and top of the cake with the remaining whipped cream. Decorate as desired and garnish with the reserved strawberries.