Instructions:

Chocolate Cake Layers: 1️⃣ Preheat the oven to 350°F (175°C). Grease and line four 8-inch cake pans with parchment paper. 🍰
2️⃣ In a bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt. 🥄
3️⃣ In another bowl, whisk warm water, buttermilk, oil, eggs, and vanilla until smooth. 🥄
4️⃣ Gradually add the wet mixture to the dry ingredients until a thin batter forms. 🍰
5️⃣ Divide the batter evenly among the pans and bake for 20-22 minutes. Cool for 10 minutes in the pans, then transfer to wire racks to cool completely. 🔥

Blackberry and Chocolate Buttercream: 6️⃣ Beat butter, vanilla, and salt until creamy. Gradually add powdered sugar. 🧴
7️⃣ Split the frosting in half. Stir ½ cup blackberry jam into one portion for blackberry buttercream. 🍇
8️⃣ Add cocoa powder, heavy cream, and melted chocolate to the other portion for chocolate frosting. Beat until smooth. 🍫

Assembling the Cake: 9️⃣ Start with one cake layer on a board. Pipe a ring of chocolate frosting around the edge and spread ⅓ cup blackberry jam inside the ring. 🍇🍫
🔟 Add a layer of blackberry buttercream and press fresh blackberries into it. 🍇
1️⃣1️⃣ Repeat the process with all layers, using the top layer upside down. 🔄
1️⃣2️⃣ Apply a crumb coat of chocolate frosting and chill for 10 minutes. ❄️
1️⃣3️⃣ Frost the cake with chocolate buttercream, adding texture with an offset spatula. Swirl blackberry buttercream on top and pipe dollops for decoration. 🍰
1️⃣4️⃣ Garnish with fresh blackberries and, if desired, gold accents for a dazzling finish. ✨