Chocolate Roll Cake with Strawberry Mousse

Instructions

For the Chocolate Cake:

1. Line a 9x13-inch (23x33cm) baking pan with parchment paper, leaving an overhang on the two shorter sides of the pan for easy lifting. Grease the paper with butter or cooking spray. 
2. Preheat the oven to 350°F (180°C) about 5 minutes before baking the cake. 
3. Sift the all-purpose flour, cocoa powder, and salt into a bowl, stir to combine, and set aside. 
4. Melt the butter in the microwave for 20-30 seconds and set aside. 
5. Place the egg whites in the bowl of an electric mixer and beat at medium speed, gradually adding the sugar in three additions. Continue beating for a few minutes until stiff peaks form. 
6. Add the vanilla and egg yolks, one at a time, beating after each addition until well incorporated into the mixture. 
7. Using a wire whisk, gently fold in the dry ingredients in three additions, alternating with the melted butter. 
8. Be sure to scrape down the sides and bottom of the bowl with a rubber spatula to prevent the butter from pooling at the bottom. Fold gently to avoid losing the air incorporated into the beaten eggs. 
9. Pour the batter into the prepared baking pan and spread it evenly with a spatula. Run a skewer or small knife throughout the dough to remove large air bubbles.
10. Bake for about 10 minutes. Do not overbake, as the cake may become too dry and crack when rolling. 
11. Run a spatula around the cake to loosen any parts that may be stuck to the pan. Remove the cake from the pan and place it on a wire rack to cool completely at room temperature. Don't remove the parchment paper, as it will be helpful while rolling the cake.

For the Filling:

1. Melt the white chocolate in the microwave in 30-second intervals, stirring until smooth. Set aside.
2. Place the cream cheese in a large bowl and mix with a whisk until creamy. You can use a stand mixer if the cream cheese has some lumps. 
3. Add the melted white chocolate and Nesquik powder to the cream cheese and stir until smooth and creamy. Set aside at room temperature while whipping the heavy cream. 
4. In the bowl of an electric mixer, beat the chilled heavy cream for a few minutes until stiff peaks form. 
5. Fold the whipped cream into the cream cheese mixture in two or three additions, gently stirring with a wire whisk until a mousse forms. 

Assembling the cake:

1. Using a serrated knife, trim the two longest edges of the cake to make them beveled.
2. Spread the filling all over the cake, with most of it piled on one of the longer sides. Using the parchment paper, start rolling the cake from that side until it reaches the other beveled edge. Remove excess filling with a spatula before closing the cake, if necessary.
3. Keep it rolled in the parchment paper to maintain its shape, and refrigerate for 3 to 4 hours or until firm. 

For the Chocolate Ganache Topping:

1. Combine the milk chocolate and room-temperature cream in a medium bowl. Microwave in 30-second intervals, stirring until smooth. 
2. Add the butter and gently stir until incorporated. The heat from the mixture will melt the butter. 
3. Chill the ganache in the fridge for 15 to 30 minutes, stirring occasionally, until it thickens. Don't leave it in the fridge for too long, otherwise the ganache will become too hard to spread.
4. Cover the cake with the chocolate ganache, creating some textures with a spatula. 
5. Dust Nesquik powder on top of the cake and keep it refrigerated until ready to serve.