1 c. unsalted butter, softened and cut into 1-in. pieces
2 Tbsp. milk
3 large eggs, room temperature
2 egg yolks
2 tsp. pure vanilla extract
1 recipe raspberry mousse filling (see below)
fresh raspberries, whipped cream and mint raspberry sauce, optional garnishes
For the raspberry mousse filling:
6 oz. (1 1/2 c.) raspberries, thawed
1/2 c. sugar, divided
1 1/2 tsp. unflavored gelatin
2 Tbsp. cold water
1 c. heavy cream
6 oz. white chocolate, melted
8 oz. plain cream cheese, softened
1 c. fresh raspberries
To prepare the cake:
Preheat the oven to 350°F/180°C. Butter the inside of an 8.5-in. loaf pan.
Combine the flour, sugar, salt and baking powder in the bowl of an electric mixer fitted with a flat paddle. Add the butter and mix on medium speed for 1 minute.
Whisk together the milk, eggs, egg yolks and vanilla. Add 1/3 of the milk mixture and mix for 1 minute. Scrape the inside surface of the bowl. Add the remaining milk mixture and continue to mix on high speed for 2 minutes. Transfer the batter into the prepared pan.
Bake on the middle rack of the oven for 50 - 55 minutes or until a toothpick inserted into the center of the cake comes out clean.
Cool the cake in the pan for 15 minutes. Remove the cake from the pan, transfer it to a wire rack and cool completely.
To prepare the filling:
In a small pan, combine the raspberries and 1/4 c. sugar; bring to a simmer over low heat, stirring often. Cook the mixture until it has reduced to 1 cup. Remove from the heat and cool to room temperature.
Combine the gelatin and water in a small microwave-safe bowl and allow the mixture to swell. Microwave the mixture for 30 seconds and stir to dissolve. Stir the gelatin into the berry mixture.
In the bowl of an electric mixer fitted with a wire whip, combine the remaining 1/4 c. sugar and the heavy cream and whip until the cream holds firm peaks. Cover and refrigerate.
In the bowl of an electric mixer fitted with a flat paddle, beat the cream cheese for 1 minute; add the melted white chocolate and mix to combine. Add the berry mixture and combine. Fold in the whipped cream and then the fresh berries.
To assemble the cake:
Line an 8.5-in. loaf pan with a sheet of parchment or wax paper with 2 in. of paper hanging over the edge of each side of the pan.
Trim the top, sides and bottom of the cake to create a neat, evenly shaped cake.
Slice the cake horizontally into 3 even layers and place one layer into the bottom of the prepared pan. Spoon half of the raspberry filling over the cake layer and spread into an even layer. Place a second layer of cake over the filling. Repeat the process finishing with a layer of cake on top.
Cover the pan with plastic wrap and refrigerate for several hours or overnight, until the filling is firm.
Remove the pan from the refrigerator. Place a serving plate or tray over the cake. Invert the pan onto the plate. Remove the pan and the paper.
Garnish the cake with fresh raspberries and whipped cream and serve with raspberry sauce, if desired.