Preheat your oven to 350°F (175°C). Grease two 8-inch springform pans with butter or oil and line the bottoms with parchment paper.

In a medium mixing bowl, sift together the flour, cocoa powder, baking soda, and salt. Set aside.

In a large bowl, whisk together the buttermilk, blackberry purée, lemon juice, and vanilla extract until smooth.

In another large mixing bowl, cream together the granulated sugar and vegetable oil until light and fluffy. Add the eggs one at a time, mixing well.

Gradually add the dry ingredients to the wet mixture, mixing on low speed until just combined.

Divide the batter evenly between the prepared pans and bake for 30-35 minutes, or until a toothpick comes out clean.

While the cake cools, prepare the frosting by beating together the cream cheese and butter until creamy. Mix in the blackberry purée, vanilla, salt, and powdered sugar until desired sweetness is achieved.

Once cakes are cool, level the tops if necessary. Layer one cake on a platter, spread frosting over the top, and add the second layer. Frost the top and sides.

Decorate with fresh blackberries, drizzle with glaze, and add any edible flowers or chocolate shards as desired. Chill briefly before slicing.

Serve and enjoy on elegant dark plates for a dramatic presentation.