Instructions

1. Preheat the oven to 325°F and grease and flour three 6 inch cake pans (you can also use 2 9 inch pans if you would rather a 2 layer cake). Set aside.
2. In a large mixing bowl fitted with a whisk attachment, beat the softened butter and oil together until they become homogenous, about 3 minutes. This will not work if your butter is not completely room temperature.
3. Slowly add the granulated sugar to the oil and butter, beating on high until the mixture is light and fluffy and turns a very pale yellow, about 3 minutes.
4. Add the eggs in one at time, scraping down the bowl in between each addition. Add the vanilla extract.
5. Beat the mixture on high for 3 minutes more to incorporate as much air as possible.
6. In separate bowl sift together the cake flour, salt, and baking powder. Alternate mixing in the dry ingredients and the buttermilk in 4 batches, starting with the buttermilk and ending with the dry ingredients. It’s okay if the batter still has a few lumps in it–you don’t want to over mix it.
7. Split the batter evenly into the prepared pans and bake for 30 minutes or until the cake is a lightly golden brown and springs back when pressed. This will depend on your oven. Take out of the oven and transfer to a cooling rack. To cool completely.
8. While the cakes cool, brew your coffee and mix the hot coffee with the sugar, stir to dissolve.
9. Make the mascarpone frosting. Combine the mascarpone, vanilla extract, powdered sugar in a stand mixer fit with the whisk attachment. Beat on medium speed until light and fluffy, about 1 minute.
10. Scrape down the bowl with a rubber spatula and turn the mixer onto medium low speed, slowly pouring in the heavy cream. Beat until smooth and fluffy and combined, about 2 minutes. Make sure to not over mix. If the cream gets too stiff it the frosting will split. Transfer the frosting to a large piping bag fit with a large round tip.
11. Place your first cake layer on a plate or cake stand and use a pastry brush to generously brush the top of the cake with the coffee syrup, really dabbing it into the cake to get it to soak it up. Pipe a layer of frosting over the cake, using an offset spatula to smooth it into an even layer if necessary.
12. Repeat with the next two cakes. Frost the top and the outside of the cake with the remaining frosting, leaving aside a bit if you’d like to decorate the top of the cake.
13. If decorating, pipe along the top of the cake in desired fashion. Sprinkle with cocoa powder to finish!
14. Refrigerate for at least two hours before serving! Enjoy!