Preheat the oven to 325 degrees F and line a pullman or loaf pan with parchment paper.

In a large bowl, whisk together the cake flour, cocoa powders, baking powder, and salt. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter and sugar for 2-3 minutes until light & fluffy.

Mixing on low speed, add the eggs one a time. Scrape down the bowl and mix in the vanilla.

Add half of the dry ingredients and mix until just combined.

Mix in the buttermilk and oil.

Add the rest of the dry ingredients and mix until just combined. Scrape down the bowl to ensure everything is evenly incorporated.

Pour the cake batter into the prepared pan and smooth out the top with an offset spatula.

Bake the cake for about 1 hour 10 minutes to 1 hour 20 minutes or until the edges begin to pull away form the sides of the pan and a toothpick inserted comes out clean.

Allow the cake to cool for a few minutes in the pan, then transfer to a wire rack to cool completely.

Once the cake has cooled completely, use a serrated knife to cut it into thirds.

Clean and line the same pullman or loaf pan with parchment paper, allowing the edges to hang over the sides for easy removal.

Place the bottom third cake layer into the pan. Scoop one pint of ice cream on top of the cake layer, and use an offset spatula to smooth it out. Add the middle cake layer, and repeat with the second pint of ice cream. Add the top cake layer, then wrap the pan in plastic wrap and freeze overnight.

Just before serving the cake, make the mascarpone frosting.

In a medium bowl, add the heavy cream, mascarpone, and sugar. Use an electric mixer to beat on low-medium speed until thick, smooth, and stiff peaks form.

Remove the ice cream cake from the pan, and place on a serving platter.

Spread the mascarpone frosting on top of the cake, and finish with crushed Oreos. Enjoy!