1/2cupsour cream or plain yogurt, (115g) room temperature
1tbsppure vanilla extract(15mL)
4 1/2cupszucchiniabout 3 medium, shredded (475g)
1 1/2cupchocolate chipssemi-sweet (265g)
For the Chocolate Buttercream:
1cupchocolate chips
2/3cupheavy cream divided (160ml)
5 1/2cupsconfectioner's sugar(680g)
1 1/2cupunsalted butterroom temperature (342g)
1/2tspsalt
1/3cupcocoa powder(40g)
1 1/2tspvanilla(7mL)
Instructions
For the Cake
Heat oven to 350 degrees and prep 3, 8-inch cake pans butter and flour or baking spray. Cut a parchment round for the bottom of each pan and place inside. I always use cake strips, which prevent my cake layers from doming.
Mix together flour, cocoa powder, baking soda, baking powder, espresso powder (optional), and salt in a large bowl. Sifting will break up any lumps of cocoa powder but is not a must.
Mix oil, granulated sugar, brown sugar, eggs, sour cream, and vanilla together in a second large bowl. If using a stand mixer use a paddle attachment.
Add the shredded zucchini to the wet mixture and mix on low to combine.
Add the dry to the wet and mix on low until almost combined then add in chocolate chips and mix until distributed. Scrape the bowl down and use a spatula to mix in any stray bits of flour etc.
Distribute cake batter evenly to your three prepared pans and bake for 30-35 minutes, or until centers are springy to the touch and a skewer inserted in the middle comes out clean.
Allow cakes to cool in pans for a couple minutes then invert onto a wire rack, and remove parchment paper rounds. Allow to cool completely
For the Chocolate Buttercream
Melt 1 cup semisweet chocolate with 1/3 cup cream then stir together and set aside to cool.
Cream the butter and salt then sift in the cocoa powder and mix until combined.
Scrape the bowl down then add the confectioner’s sugar in a few batches alternating with the cream. Add the vanilla and melted and cooled chocolate then increase speed to high and beat for 3-5 minutes until light and fluffy. Scrape the bowl down one last time and mix once more.
For the Assembly:
Pipe buttercream onto the first layer. Add second layer and repeat.
Apply a thin coat of buttercream to the side and top then smooth.
Pipe dollops of buttercream on the top's edge using an 869 or any large star tip.
Video
Notes
Make sure to measure your flour correctly Adding too much flour to the recipe is the most common mistake. The best and easiest way to measure flour is by using a kitchen scale. If you don't have one then fluff your flour with a spoon, sprinkle it into your measuring cup, and use a knife to level it off.
Use three 8 inch cake pans so each layer is high and uniformed.
Make sure to prepare your cake pans, grease them in butter then dust them in flour getting rid of any excess. Place a round piece of parchment paper at the bottom of each pan. This will make sure that your cake won't stick and will give you an easy release.
The zucchini grates really easily and quickly using the big holes on a box grater. You can use a food processor if you don't have one.
If the zucchini seems extra wet squeeze out any excess moisture.
Make sure your refrigerated ingredients are at room temperature before starting especially the eggs!
To test that the cake is ready insert a small skewer or toothpick into the center of the cake, if it comes out clean it's ready.
To get uniform flat layers that are moist inside and out try using cake strips! You can buy a set on theshop page or make your own from foil and paper towels at home. I made a wholeblog post on it so check it out if you’re interested!
Make sure the cake is cooled completely before frosting.
Your butter should be softened at room temperature before making the buttercream or it'll be lumpy and unpleasant.
I like to use a star tip to pipe some frosting around the top edge of the cake. I used an 869 tip but any larger star tip will work well.
You can use the batter to make cupcakes instead of a whole cake.
Storage - this cake will keep well for 4-5 days or can be frozen for up to 3 months. Wrap in plastic wrap and foil then defrost thoroughly before serving.