Preheat your oven to 325°F. Liberally prepare 3 9-inch round cake pans with the nonstick method of your choice. (I recommend the parchment method described on p. 17.)

In the bowl of your stand mixer fitted with the whisk attachment, add the flour, granulated sugar, cocoa powder, baking soda, and salt and mix on low speed. Slowly add the oil and buttermilk.

Increase the speed to medium-low and add the eggs 1 at a time, combining well after each addition and scraping down the sides and bottom of the bowl as needed. Slowly add the coffee, vanilla extract, vinegar, and food coloring. Scrape down the sides and bottom of the bowl and mix the batter until just combined. Be careful not to overmix.

Evenly pour the batter into the prepared pans and bake for 20 to 27 minutes, or until a toothpick inserted into the center of a layer comes out clean. Do not overbake.

Let the layers cool in the pans for 10 minutes, then invert onto wire racks. Let cool to room temperature. Lightly cover the cakes with foil or plastic wrap so they do not dry out.

In a medium saucepan over medium heat, warm the blackberries, granulated sugar, lime juice, and salt. Once the blackberries begin releasing their juices and the liquid begins to boil, after about 8 to 12 minutes, use a pastry cutter or fork to mash 1/2 of the berries. Leave the rest whole.

Stir in the cornstarch and continue to cook at a boil, allowing the juices to cook down and thicken. The compote is ready when the liquid coats and completely sticks to the back of a spoon. Remove from the heat. Let cool to room temperature.

Clean your stand mixer bowl and whisk attachment. Beat the cream cheese on high speed until it begins to thicken and become fluffy.

Turn your mixer down to low speed and carefully add the confectioners’ sugar. Once the sugar is fully incorporated, turn your mixer speed back up and continue whipping. Add the heavy cream, vanilla extract, and salt. Continue to whip until the frosting is smooth, light, and fluffy. Refrigerate the buttercream for 30 minutes to firm it up.

Once the layers are completely cooled, place 1 layer on a serving plate. Spread just the top with 1/3 of the frosting (please refer to the Basic Frosting Instructions on p. 18). Add 1/3 of the compote over the frosting. Using a butter knife or skewer, swirl the compote into the frosting. Add the second layer and spread with another 1/3 of the frosting. Add 1/3 of the compote, swirling the compote into the frosting again. Add the final layer, bottom-side up, and top with the remaining frosting. Add the rest of the compote and repeat the swirling process. Do not frost the side of the cake. Garnish with the whole blackberries. Serve at room temperature. Store in the refrigerator.