Preheat the oven to 350°F (175°C). Grease and flour an 8-inch round cake pan.
In a medium bowl, sift together the all-purpose flour, unsweetened cocoa powder, baking powder, baking soda, and salt.
In a large bowl, whisk the granulated sugar, whole milk, vegetable oil, eggs, and vanilla extract until smooth and combined.
Gradually add the dry ingredients to the wet ingredients, mixing gently until just combined.
Carefully pour in the boiling water and stir until the batter is smooth and slightly thin.
Pour the batter into the prepared cake pan and bake for 28 to 30 minutes, or until a toothpick inserted into the center comes out clean.
Remove the cake from the oven and let it cool in the pan for 10 minutes. Then transfer it to a wire rack to cool completely.
While the cake cools, prepare the chocolate ganache by heating the heavy cream in a small saucepan over medium heat until it just begins to simmer.
Pour the hot cream over the chopped dark chocolate in a heatproof bowl. Let it sit for 2 minutes, then stir gently until smooth and glossy. Allow it to cool to room temperature.
Whip the powdered sugar into the cooled ganache until it thickens slightly but remains spreadable.
Once the cake is completely cooled, spread the chocolate ganache evenly over the top and sides of the cake using a spatula.
Decorate the cake with sliced fresh strawberries arranged neatly on top, and place small pieces of edible gold leaf delicately for a refined Korean aesthetic touch.
Refrigerate the cake for at least 30 minutes before serving to set the ganache.