01 - Preheat the oven to 350°F. Grease and line an 8-inch square baking pan with parchment paper.
02 - In a large bowl, whisk together flour, granulated sugar, cocoa powder, baking powder, baking soda, and salt until well blended.
03 - Add buttermilk, vegetable oil, egg, and vanilla extract to the dry mixture. Mix until smooth, then pour in hot water and stir until fully incorporated.
04 - Pour batter into prepared pan. Bake for 25-30 minutes or until a toothpick inserted in center comes out clean. Cool completely on wire rack.
05 - While cake cools, whip heavy cream with powdered sugar, vanilla, and softened cream cheese until medium-stiff peaks form. Keep refrigerated until assembly.
06 - Break cooled cake into small pieces and crumble into fine, soil-like texture using hands or fork.
07 - Layer crumbled cake in bottom of clean flower pots or dessert cups. Add creamy filling layer. Top with another cake crumb layer. Generously cover surface with chocolate cookie crumbs to simulate soil.
08 - Arrange edible flowers, mint leaves, and herb sprigs on top to create garden appearance. Refrigerate at least 30 minutes before serving for optimal texture.