Preheat oven to 350. Grease and flour a 13x9 cake pan.

In a saucepan, bring 1/2 cup butter, 1 cup Coke, and oil to a boil.

Combine flour and sugar and add to saucepan and beat together, then remove from heat.

Add in remaining cake ingredients. Mix well and pour into prepared pan.

Bake for 30 minutes or until toothpick inserted in center comes out clean.

Melt chocolate chips in microwave 30 seconds at a time, stirring each time. Add in the rest of the ingredients and whisk together.

Poke holes in cake. 2 ways you can do this. Either use the end of a wooden spoon or using a fork, poke the cake all over, depending how you want your chocolate filling to soak through. I did the wooden spoon, but both would be fine.

Pour the chocolate filling into the holes and all over the top of the cake while it's still warm.

Put in fridge to set about 40 minutes.

Using mixer, whip the whipping cream until stiff peaks, then add in the chocolate extract, coke, powdered sugar and mix together lightly.

Using a spatula, frost the top of the chocolate filled cake with the whipped cream frosting.

Place back in fridge.

Put hot fudge in a microwavable dish and microwave on high for 15-20 seconds or until pourable. Do not pour on top of cake if it's hot. Once cooled and still pourable, drizzle on cake and then using a toothpick or knife edge, swirl the chocolate around.

Using a grater, grate some chocolate on top and place back in the fridge overnight.

Enjoy!