Preheat oven to 350 degrees F. Grease two 9x2-inch round cake pans, line the bottoms with parchment paper, grease the parchment and flour the pans. Set aside.
In a medium bowl, sift together the flour, baking soda, baking powder, and salt. Set aside.
Using an electric mixer, cream the butter and sugar on medium speed for 3 minutes, until light and fluffy. On low speed, add the eggs, on at a time. Add the oil and vanilla and beat until well mixed, scraping down the bowl with a rubber spatula.
In a small bowl, whisk together the cocoa powder and hot coffee until smooth. With the mixer on low, add the chocolate mixture to the batter.
Still with the mixer on low, slowly add half of the flour mixture to the batter, then all of the sour cream, then the remaining flour mixture, mixing each addition until combined. With a rubber spatula, fold the batter until it is well mixed.
Divide the batter evenly between the two prepared pans and smooth the tops. Bake for 30 to 40 minutes, until a toothpick inserted into the center comes out clean. Col in the pans for 30 minutes, then turn the cakes out onto a wire rack and cool completely.
Slice each cake layer in half horizontally. Place the bottom of the first cake, cut side up, on a flat serving plate and spread 1 cup of frosting on the top. Place the top of the first cake, cut side down, on top and spread another 1 cup of frosting on top. Next, place the top layer of the second cake on top, cut side up, and frost with another 1 cup of frosting. Finally, place the bottom layer of the second cake, bottom side up (so the top of the cake is flat). Frost the top and sides of the cake. The cake can be stored, covered, for up to 3 days. If you use the meringue buttercream, the cake should be refrigerated; bring to room temperature prior to serving. If you use any other type of frosting (a traditional vanilla, chocolate, cream cheese, etc.), the cake can be stored at room temperature.