Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.

In a large mixing bowl, sift together the flour, sugar, cocoa powder, baking powder, baking soda, and salt. Add the eggs, milk, vegetable oil, and vanilla extract. Beat on medium speed for 2 minutes. Stir in the boiling water - the batter will be thin. Pour the batter evenly into the prepared pans.

Bake for 30 to 35 minutes, or until a toothpick inserted into the center comes out clean. Remove from the oven and let the cakes cool in the pans for 10 minutes. Then, transfer them to a wire rack to cool completely.

To make the glaze, combine the sugar, water, heavy cream, and cocoa powder in a small saucepan. Cook over medium heat, stirring constantly, until the sugar is dissolved and the mixture comes to a boil. Remove from the heat.

In a separate small bowl, sprinkle the powdered gelatin over the cold water and let it sit for a minute to soften. Then, add the gelatin mixture to the hot glaze mixture and stir until the gelatin is completely dissolved.

To make the chocolate ganache, heat the heavy cream in a small saucepan over medium heat until it begins to steam. Remove from the heat and add the chopped chocolate. Let it sit for a minute to melt, then stir until smooth. Stir in the butter until melted and combined.

To assemble the cake, place one cooled cake layer on a serving plate. Pour half of the glaze over the top, allowing it to trickle down the sides. Let it set for a few minutes. Then, spread half of the chocolate ganache over the glaze. Place the second cake layer on top and repeat the glaze and ganache process.

Refrigerate the cake for at least 1 hour to allow the glaze and ganache to set. Serve chilled and enjoy!