1. Make the Cake: Preheat oven to 350°F (175°C). Grease and line a loaf pan. Whisk flour, cocoa, baking soda, and salt. In another bowl, beat sugar, oil, eggs, and vanilla until smooth. Mix in sour cream. Gradually add dry ingredients and hot water. Pour into pan and bake for 35–40 minutes. Cool completely.
2. Prepare Raspberry Filling: In a saucepan, combine raspberries, sugar, lemon juice, and cornstarch mixed with water. Cook on medium until thickened (5–8 mins). Let cool.
3. Ganache: Heat cream until simmering, pour over chocolate. Let sit 2 mins, then stir until glossy.
4. Assemble: Slice cake in half. Spread raspberry filling over bottom layer. Top with second layer. Pour ganache over the cake and let drip. Top with fresh raspberries.