01 - Preheat the oven to 350°F. Grease and flour two 9-inch round cake pans, ensuring even coverage on all surfaces.
02 - Sift together the all-purpose flour, granulated sugar, unsweetened cocoa powder, baking powder, baking soda, and salt in a large mixing bowl.
03 - Add the eggs, whole milk, vegetable oil, and vanilla extract to the dry mixture. Beat until just combined. Gradually pour in the boiling water while mixing continuously until the batter is smooth and uniform. The batter will be quite thin — this is normal.
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 sliced strawberries with granulated sugar and lemon juice in a bowl. Set aside for at least 20 minutes to allow the fruit to release its natural juices and develop flavor.
06 - Heat the heavy cream in a saucepan over medium heat just until it begins to simmer — do not boil. Pour the hot cream over the chopped semisweet chocolate in a heatproof bowl. Let it sit undisturbed for 2 minutes, then stir gently from the center outward until the mixture is glossy and smooth. Allow the ganache to cool and thicken slightly until it reaches a pourable consistency.
07 - If using the whipped topping, beat the heavy whipping cream with powdered sugar and vanilla extract in a chilled bowl until soft peaks form. Be careful not to overwhip.
08 - Place one cooled cake layer on a serving platter. Arrange a generous layer of macerated strawberries over the top, reserving several slices for garnish. Spread half of the chocolate ganache evenly over the strawberries. If desired, add a layer of whipped cream on top of the strawberry layer.
09 - Carefully position the second cake layer on top. Pour the remaining ganache over the surface, allowing it to flow naturally down the sides. Arrange the reserved strawberry slices on top as garnish.
10 - Refrigerate the assembled cake for at least 1 hour to allow the layers and ganache to set properly. Slice into wedges and serve chilled.