Make the chocolate sponge

• Preheat oven to 180°C (350°F). Line two 8-inch pans with parchment.
• Whisk eggs, oil, vanilla, sour cream, salt, buttermilk, sugar, and ½ of the cocoa in a large bowl until smooth.
• Add flour, baking powder, and baking soda. Whisk until just visible streaks of flour remain.
• Bloom the Cocoa: Pour in the hot coffee mixed with ½ of the cocoa powder. Whisk gently until the batter is smooth.
• Divide batter evenly (use a scale for precision). Bake for 30 minutes or until a toothpick comes out clean.
• Release edges with a thin spatula. Invert onto a wire rack and cool completely before frosting.

Make the strawberry filling

• Combine chopped strawberries, sugar, and lemon juice in a saucepan over medium-high heat. Reduce to medium-low. Simmer for 20 minutes, stirring occasionally.
• Whisk cornstarch with a splash of water; stir into berries. Simmer for 2 minutes until glossy. Cool completely to room temperature (it will thicken further).

Make the strawberry cream cheese frosting

• Beat softened cream cheese and butter until smooth and aerated. Gradually add powdered sugar on low speed until fully incorporated.
• Mix in strawberry compote (from step 2), vanilla, and salt. Beat on medium until smooth and holdable.

Assembly

• Pipe a thick ring of frosting around the edge of the first cake layer to create a "dam." Pour the cooled strawberry filling into the center of the dam. Top with the second cake layer.
• Frost the top and sides. Press paper-towel-dried strawberry halves onto the frosting for decoration.