01 - Preheat oven to 350°F. Grease and line an 8-inch square baking pan.
02 - Whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt in a large bowl.
03 - Add buttermilk, oil, egg, and vanilla to the dry mixture. Mix until smooth. Pour in hot water and mix again.
04 - Pour batter into prepared pan. Bake for 25-30 minutes until toothpick inserted comes out clean. Cool completely.
05 - Whip heavy cream with powdered sugar and vanilla (and cream cheese if using) until medium-stiff peaks form. Keep chilled.
06 - Break cooled cake into small crumbled pieces.
07 - Layer crumbled cake, creamy filling, and more cake crumbs in clean flower pots or dessert cups.
08 - Generously top with chocolate cookie crumbs to resemble soil.
09 - Decorate with edible flowers, mint leaves, and herb sprigs to create garden effect.
10 - Refrigerate for at least 30 minutes for best texture.