Step 1: Bake the Chocolate Cake

1. Preheat your oven to 350°F (175°C). Grease and line two 9-inch round cake pans with parchment paper.
2. In a large mixing bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt.
3. Add buttermilk, vegetable oil, eggs, and vanilla extract. Mix until just combined.
4. Gradually pour in the hot water, stirring until the batter is smooth.
5. Divide the batter evenly between the pans. Bake for 30–35 minutes, or until a toothpick inserted in the center comes out clean.
6. Cool in pans for 10 minutes, then transfer to a wire rack to cool completely.

Step 2: Prepare the Raspberry Filling

1. In a medium saucepan, combine raspberries, sugar, and lemon juice. Cook over medium heat until raspberries break down.
2. Mix cornstarch with 2 tablespoons of water to form a slurry, then add it to the raspberry mixture. Stir continuously until thickened.
3. Let cool completely. For a smoother texture, strain the mixture to remove seeds.

Step 3: Make the Chocolate Ganache

1. Heat heavy cream in a small saucepan until it just begins to simmer.
2. Pour over chocolate chips in a heatproof bowl. Let sit for 2–3 minutes, then stir until smooth and glossy.
3. Allow ganache to cool slightly until it thickens to a spreadable consistency.

Step 4: Assemble the Cake

1. Place one cooled cake layer on a serving plate. Spread raspberry filling evenly over the top.
2. Add the second cake layer and press down gently.
3. Pour ganache over the top, letting it drip down the sides. Smooth with an offset spatula if needed.
4. Decorate with fresh raspberries, chocolate shavings, or edible flowers as desired.