01 - Preheat oven to 350°F. Grease and line an 8-inch square baking pan with parchment paper.
02 - In a large bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt until well combined.
03 - Add buttermilk, vegetable oil, egg, and vanilla extract to the dry mixture. Beat until smooth, then pour in hot water and mix until incorporated.
04 - Pour batter into prepared pan. Bake for 25 to 30 minutes until a toothpick inserted in center comes out clean. Cool completely in pan.
05 - Whip heavy cream with powdered sugar and vanilla extract until medium-stiff peaks form. If using cream cheese, beat until smooth before folding into whipped cream. Keep chilled.
06 - Break cooled cake into small crumbles using hands or a fork. Set aside for assembly.
07 - Fill clean flower pots or dessert cups with a layer of cake crumbles, followed by a layer of cream filling. Repeat with another layer of cake crumbs.
08 - Generously sprinkle chocolate cookie crumbs over the top layer to create a realistic soil appearance.
09 - Arrange edible flowers, mint leaves, and herb sprigs on top to resemble a planted garden. Chill assembled desserts for at least 30 minutes before serving.