Sift the flour, sugar, cocoa, baking soda, baking powder, and salt into the bowl and mix until combined.

In another bowl, combine the buttermilk, oil, eggs, and vanilla.

With the mixer on low speed, slowly add the wet ingredients to the dry. With mixer still on low, add the coffee and stir just to combine, scraping the bottom of the bowl with a rubber spatula. Pour the batter into two 8-inch round prepared pans and bake for 30 to 40 minutes at 350°F, until a cake tester or toothpick comes out mostly clean (not wet).

Cool in the pans for 30 minutes, then turn them out onto a cooling rack and cool completely.

In the bowl of an electric stand mixer fitted with whisk attachment, whisk butter and sugar on medium-high speed until very pale and fluffy or about five minutes.

Be sure to stop at least once and scrape the bowl.

With the mixer off, add in dark cocoa powder, vanilla and salt.

Turn mixer on low and blend for about 30 seconds.

One tablespoon at a time add in heavy cream.

Once all cream has been added and mixture is mostly combined, turn off the mixer and scrape down the sides of the bowl.

Add in 1 teaspoon of black food color.

Now turn the mixer onto medium-high to high and whisk for 3-5 minutes or until mixture is lighter and fluffier.

Follow the instructions on the pudding box, adding the lime extract and food color to the mixture as you blend ingredients. Cover the mixture and place it in the refrigerator for at least an hour, or until you are ready to use it.