Step 1: Preheat your oven to 350°F (175°C). Grease and flour your cake pans to prevent sticking.
Step 2: In a large mixing bowl, whisk together the flour, cocoa powder, baking powder, baking soda, sugar, and salt until well combined.
Step 3: In another bowl, whisk together the eggs, milk, canola oil, and vanilla extract until smooth.
Step 4: Gradually add the wet ingredients to the dry ingredients, mixing until just combined. Be careful not to overmix; a few lumps are okay.
Step 5: Pour in the boiling water and mix until the batter is smooth. The batter will be quite thin, don’t worry, that’s how it should be!
Step 6: Divide the batter evenly between the prepared cake pans. Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean.
Step 7: Once baked, remove the cakes from the oven and let them cool in the pans for about 10 minutes. Then, turn them out onto a cooling rack to cool completely.
Step 8: While the cakes cool, prepare your mirror glaze. You can find various recipes online, but it typically involves gelatin, sugar, and chocolate.
Step 9: Once the cakes are completely cool, level them with a serrated knife if necessary. Place one layer on a serving plate, spread a layer of frosting on top, then add the second layer.
Step 10: Pour the prepared mirror glaze over the top of the cake, allowing it to drip down the sides for that stunning effect.
Step 11: Chill the assembled cake in the refrigerator for at least 30 minutes before serving to set the glaze. Slice and enjoy your beautiful Layered Chocolate Mirror Cake!