Preheat your oven to 355°F (180°C).
Grease a 10″x 12″ baking pan.
Boil the water either in a pot (stove) or microwave.
In a large mixing bowl with paddle-attachment (or hand mixer) add the cocoa and pour in the hot water and mix until well combined and smooth.
Add in the milk and canola oil and mix until combined.
Add the salt and baking soda and continue to mix for about 40 seconds.
Add in the eggs, and vanilla extract and mix until well combined and batter looks smooth.
Add in the sugar and mix for 60 seconds
add in the flour slowly and mix for 2 minutes or until batter is shiny and smooth.
Pour batter into greased baking pan
Bake for 35-45 minutes or until surface of cake springs back.
Once cake is baked remove from the oven and cool in baking pan for 40 minutes.
Place into freezer for 2 hours.
Add the butter and salt into mixing bowl and mix with paddle attachment until fluffy and light yellowish color. You can also use a hand mixer if you don’t have a stand mixer.
Once the butter is fluffy add in the vanilla extract and mix until buttercream is smooth light and fluffy.
Add in the milk and and mix until smooth about 30-40 seconds.
Fill a pastry piping bag with the buttercream icing with 1/2 inch round tip. Put into refrigerator 15 minutes just before using.
Remove cake from freezer and pipe the buttercream across the shorter part of the cake about 1 inch apart. Put cake back into freezer for 20 minutes.
LIQUID CHOCOLATE FUDGE FROSTING INSTRUCTIONS
in a medium size pot add the corn syrup, buttermilk, cocoa, and salt and cook on medium heat until it start to bubble on the surface, about 3-5 minutes.
Turn the heat to low and add add the icing sugar. Mix using a whisk until the sugar has completely melted and is smooth and shiny.
Remove from the pot from heat and add in the vanilla extract and mix with whisk until well combined. Pour this into a large measuring glass and set aside just until it cools down;warm to the touch.
Remove the cake from the freezer and pour about half of the chocolate frosting To finish: Remove the cake from the freezer and pour half of the warm fudge frosting over the cake in long streaks over the buttercream bumps.
Lift pan and tilt from side to side until top of cake is coated with the frosting.
Place back into freezer for 15 minutes.
Pour the rest of the frosting over the buttercream bumps and tilt again covering the surface of the cake. If the chocolate frosting sets before pouring, microwave for a few seconds then add to cake.
Once cake is completely coated place into refrigerator for 30 minutes before serving.