1. Prepare three 8 inch cake pans with parchment paper circles in the bottom and grease the sides. The cranberries in this cake have a tendency to stick in the corners of the pan, so grease them well. Preheat the oven to 350°F (176°C).
2. Combine 2 1/2 cups of flour (325g), cornstarch, baking powder, baking soda and salt in a medium sized bowl and set aside.
3. Add the butter, sugar, oil and vanilla extract to and large mixer bowl and beat together until light in color and fluffy, about 2-3 minutes. Do not skimp on the creaming time.
4. Add the eggs one at a time, mixing until mostly combined after each. Scrape down the sides of the bowl as needed to be sure all ingredients are well incorporated.
5. Add half of the dry ingredients to the batter and mix until mostly combined.
6. Add the milk and sour cream and mix until well combined, but don’t over mix.
7. Add the remaining dry ingredients and mix until well combined and smooth. Scrape down the sides of the bowl as needed to be sure all ingredients are well incorporated. Do not over mix the batter.
8. Add the cranberries and remaining tablespoon (8g) of flour to a bowl and stir to coat the cranberries in flour.
9. Add the cranberries to the batter and gently stir to combine.
10. Divide the batter evenly between the cakes pans and bake for 28-32 minutes, or until a toothpick comes out with a few crumbs.
11. Remove the cakes from the oven and allow to cool for about 2-3 minutes, then remove to cooling racks to cool completely.
12. To make the frosting, beat the butter and shortening together until smooth.
13. Slowly add half of the powdered sugar and mix until smooth.
14. Add 3 tablespoons of water or milk and mix until smooth.
15. Slowly add the remaining powdered sugar and mix until smooth. Frosting will be very thick.
16. Remove about 2 1/2 cups of frosting for the chocolate frosting and add 3 tablespoons of water or milk. Mix until combined.
17. Add the cocoa powder and mix until well combined. Add additional milk or water, if needed.
18. For the remainder of the frosting, add the vanilla extract and another 2-3 tablespoons of water or milk, until your frosting is the right consistency.
19. Remove about 3/4 cup of the vanilla frosting and set the rest aside. Add some pink and red gel icing color to the 3/4 cup of frosting to get a nice shade of pink/red.
20. To put the cake together, use a large serrated knife to remove the domes from the top of the cakes (if needed) so that they’re flat. These cakes don’t have a large dome, but I often like to make sure they’re completely flat. See my tips on how to level a cake and how to stack a cake.
21. Place the first cake on a serving plate or a cardboard cake round.
22. Spread about 1 cup of chocolate frosting evenly on top of the cake.
23. Add the second layer of cake and another cup of chocolate frosting.
24. Top the cake with the remaining layer and partially frost the outside of the cake with white vanilla frosting. Refer to my tutorial for frosting a smooth cake, if needed. After the sides of the cake are mostly frosted, but not completely finished, move to the next step.
25. Place some dots of chocolate frosting and the pink/red frosting around the outside of the cake (see photo in post above), then use an icing smoother or offset spatula to spread it around the outside of the cake. It should naturally blend the three colors together.
26. Finish frosting the top of the cake, then make the chocolate ganache (see my tips on making chocolate ganache).
27. Place the chocolate chips in a small bowl. Heat the heavy whipping cream until it begins to boil, then pour over the chocolate chips.
28. Allow the chocolate and cream to sit for about a minute, then whisk until smooth.
29. Drizzle the chocolate around the sides of the cake, creating drips, then fill in the center of the top of the cake. I like to use a squeeze bottle for creating the drips, but a piping bag and tip would work as well. See my tips on making a chocolate drip cake.
30. Pipe a border around the top edge of the cake using the remaining pink/red frosting.
31. To finish off the cake, add some fresh cranberries and mini chocolate chips, if desired.