Preheat the oven to 175°C (350°F). Grease and flour two 8 x 9-inch pans.
In the bowl of a mixer, combine the sugar, flour, cocoa powder, baking powder, baking soda, and salt. Whisk together until fully combined. Add the eggs, milk, oil, and vanilla; beat on medium speed for 2 minutes.
Scrape the sides of the bowl, then slowly stir in the boiling water. Pour batter evenly into the prepared pans and bake using the convectional function for 30 to 40 minutes, until the tops of the cakes spring back when lightly touched in the centre.
Remove the cakes from the oven. Let cool in the pans for 10 minutes, then remove to finish cooling on wire racks.
Prepare the Frosting. In the bowl of a mixer, beat the butter, cream, and both extracts on medium speed until smooth. With mixer speed on low, slowly add the powdered sugar and mix until just combined. Add the food colouring and increase the speed to medium-high. Beat for a minute until the frosting is light, smooth, and fluffy. Add the chopped chocolate and beat on low until mixed. Frost cooled cakes.