01 -
Preheat oven to 175°C. Grease a 23 x 33 cm baking dish with baking spray and set aside. Place chocolate chips in a medium bowl. Heat whole milk to 82-88°C and pour over chocolate; let sit 5 minutes without stirring. Whisk until smooth and glossy, then blend in sour cream. Set aside.
02 -
In a separate bowl, whisk together sifted cake flour, cocoa powder, baking soda, and fine sea salt until evenly mixed. Set aside.
03 -
In a large bowl, beat light brown sugar and vegetable oil with an electric mixer until creamy. Add vanilla extract, then incorporate eggs one at a time, mixing thoroughly after each addition.
04 -
Alternately add half of the dry flour mixture and half of the chocolate mixture to the wet ingredients, mixing gently after each addition until just combined. Repeat with remaining dry and chocolate mixtures, avoiding overmixing to preserve tenderness.
05 -
Pour batter into prepared pan and smooth the surface. Bake for 30-35 minutes until a toothpick inserted centrally comes out clean. Cool completely before proceeding.
06 -
Whisk whole milk and all-purpose flour in a small saucepan until smooth. Heat over medium, stirring constantly until thickened into a paste. Remove from heat and cool to room temperature.
07 -
Beat unsalted butter and vegetable shortening until smooth. Gradually add powdered sugar, beating thoroughly after each addition. Incorporate cooled milk-flour paste and vanilla extract. Continue beating at medium-high speed for 3 minutes until fluffy and light.
08 -
Spread cream filling evenly over cooled cake using an offset spatula for a smooth finish. Refrigerate while preparing ganache.
09 -
Place chocolate chips in a bowl. Heat heavy cream to 82-88°C and pour over chocolate. Let stand 5 minutes, then whisk until smooth and glossy. Allow ganache to cool about 10 minutes to thicken slightly.
10 -
Pour ganache evenly over cream filling. Refrigerate uncovered for at least 45 minutes to allow ganache to set firmly and filling to thicken. Serve chilled for optimal texture and flavor.