01 - Preheat oven to 350°F (175°C). Grease and flour two 9-inch round cake pans, then line the bottoms with parchment paper for easy release.
02 - In a large mixing bowl, sift together the all-purpose flour, granulated sugar, unsweetened cocoa powder, baking powder, baking soda, and salt until evenly distributed and free of lumps.
03 - Add the eggs, whole milk, vegetable oil, and vanilla extract to the dry mixture. Beat on medium speed until fully combined. Gradually pour in the boiling water while mixing continuously until the batter is smooth and velvety. The batter will appear quite thin — this is expected.
04 - Divide the batter evenly between the two prepared cake pans. Bake for 30 to 35 minutes, or until a toothpick inserted into the center of each layer comes out clean. Allow the cakes to rest in the pans for 10 minutes, then invert onto wire racks to cool completely.
05 - While the cakes bake, toss the hulled and sliced strawberries with granulated sugar and fresh lemon juice. Set aside at room temperature for at least 20 minutes to allow the juices to release and the flavors to intensify.
06 - In a small saucepan, heat the heavy cream over medium heat until it just begins to simmer — do not allow it to boil. Remove from heat and pour over the chopped semisweet chocolate in a heatproof bowl. Let stand for 2 minutes, then stir gently from the center outward until the ganache is glossy and smooth. Allow it to cool until thickened slightly but still pourable.
07 - If using the whipped cream topping, combine the heavy whipping cream, powdered sugar, and vanilla extract in a chilled bowl. Whip with an electric mixer on medium-high speed until soft peaks form. Be careful not to overwhip.
08 - Place the first cake layer on a serving platter. Arrange a generous layer of the macerated strawberries over the top, reserving a handful for garnish. Drizzle half of the chocolate ganache evenly over the strawberries. If desired, spread a layer of whipped cream over the strawberry filling for added richness.
09 - Carefully position the second cake layer on top. Pour the remaining ganache over the crown of the cake, allowing it to cascade naturally down the sides. Arrange the reserved strawberries on top as garnish.
10 - Refrigerate the assembled cake for at least 1 hour to allow the layers to set and the flavors to meld. Slice with a sharp knife warmed under hot water for clean portions. Serve chilled or at room temperature.