Step 1: Preheat your oven to 350°F (175°C). Grease and flour two 8-inch round cake pans or line with parchment paper.
Step 2: In a large bowl, whisk together the flour, granulated sugar, cocoa powder, baking soda, baking powder, and salt.
Step 3: Add the buttermilk, vegetable oil, eggs, and vanilla extract to the dry ingredients. Beat with an electric mixer on medium speed until just combined.
Step 4: Carefully stir in the boiling water until the batter is smooth. The batter will be thin.
Step 5: Divide the batter evenly between the prepared cake pans. Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean.
Step 6: Let the cakes cool in the pans for 10 minutes before inverting them onto a wire rack to cool completely. Once cool, level the tops if needed.
Step 7: For the strawberry filling, combine diced strawberries, 1/2 cup granulated sugar, and lemon juice in a medium saucepan. Cook over medium heat, stirring occasionally, until the strawberries break down and the mixture thickens slightly, about 10-15 minutes. Stir in 1 teaspoon vanilla extract. Let cool completely.
Step 8: In a large bowl, beat the softened cream cheese, powdered sugar, and 1 teaspoon vanilla extract until smooth and creamy.
Step 9: In a separate, chilled bowl, whip the very cold heavy cream until stiff peaks form.
Step 10: Gently fold about one-third of the whipped cream into the cream cheese mixture until combined. Then, fold in the remaining whipped cream until no streaks remain.
Step 11: To assemble the cake: Place one chocolate cake layer on a serving plate or cake stand. Spread half of the strawberry filling over the cake layer, leaving a small border.
Step 12: Spread half of the cream cheese whipped cream mixture evenly over the strawberry filling.
Step 13: Carefully place the second chocolate cake layer on top. Repeat with the remaining strawberry filling and cream cheese whipped cream mixture.
Step 14: For the chocolate ganache (optional, but highly recommended for the 'bomb' effect): Heat 1 cup heavy cream until simmering, then pour over 8 ounces chopped semi-sweet chocolate. Let sit for 5 minutes, then whisk until smooth. Let cool slightly until thickened but still pourable.
Step 15: Pour the cooled ganache over the top of the cake, allowing it to drip down the sides.
Step 16: Garnish with fresh strawberries. Chill the cake for at least 2-3 hours (preferably overnight) before slicing and serving. This allows the flavors to meld and the cake to set beautifully.