Step 1

Preheat the oven to 350 degrees and lightly grease a 9x13" pan  (line with parchment paper if desired).

Step 2

In a large bowl, whisk together sugar, buttermilk, eggs, and vanilla until smooth.

Step 3

Add flour, cocoa powder, baking soda, salt, and baking powder and stir until combined.

Step 4

Stir in zucchini, just until combined.

Step 5

Spread into prepared pan and bake for 30-34 minutes, until a toothpick inserted in the center comes out clean or with moist crumbs. Set aside to cool to room temperature.

Step 6

In a medium bowl, combine cream, sugar, cocoa, and vanilla.

Step 7

Beat with an electric mixer on low until incorporated, then beat on high until stiff peaks form.

Step 8

Spread over cooled cake and serve.