Chocolate Zucchini Cake with Blackberry Buttercream Frosting

 I’m very proud to say that my garden is growing beautifully this year – the tomatoes (my favorite!) are coming along nicely – the plants are huge and have tons of fruit, I’m just waiting (im)patiently for them to turn red. The zucchini – also ginormous – are already producing like the champs they are.


This year’s zucchini have been restorative for me – everyone talks about how easy it is to grow, and while I’ve historically had luck producing great big zucchini plants, I’ve had no luck growing the actual vegetable. Not sure what I did wrong in years past, but I’m excited to figure out what to do with this year’s abundant crop.


The other season that’s closing in on us here in the PNW is blackberries – Himalayan blackberries grow as an invasive plant all around the area. I’d never want in my yard, but it does mean that we can find them everywhere (and it’s not uncommon to see folks snacking  directly off the branches). Every summer, we (Brandon) picks a bunch, then we (me) freeze them for use throughout the year. In rooting through the freezer, I came across a small bag from last summer – with a new year of blackberries upon us, I figured this was the perfect opportunity to use up what we have.





Here’s the deal with this cake: the zucchini is great, because you can’t taste it all all, but it adds some nice moisture to the cake. And the frosting is delicious because – well – it’s fresh blackberries and buttercream mixed together for a lovely sweet and slightly tart frosting.





Chocolate Zucchini Cake


1 1/2 cup white sugar

3/4 cup (1 1/2 sticks) butter, room temperature

2 large eggs

2 1/4 cup all purpose flour

1/2 cup unsweetened cocoa powder

1 teaspoon baking soda

1 teaspoon salt

1 teaspoon vanilla

3/4 cup buttermilk

2 cups grated zucchini

1 1/2 cups semi or bittersweet chocolate chunks


Preheat oven to 325 degrees. Coat 9×13 baking pan or bundt pan lightly with cooking spray, and set aside


In the bowl of a stand mixer, using the paddle attachment, cream the butter and sugar together until light and fluffy, about 3-4 minutes. Add eggs, one at at time.


In a large bowl, sift together the flour, cocoa powder, baking soda, and salt.


In a separate bowl, stir together the vanilla and buttermilk.


Alternate adding the dry ingredients and buttermilk mixture in to the butter/sugar/eggs. Start with the dry ingredients, and end with the wet, each time beating just until the ingredients are incorporated (be careful not to over mix!).


Add the zucchini and chocolate chunks, and stir by hand until incorporated. The batter will be thick. Pour in to prepared pan and bake for 50-60 minutes, removing from the oven when a toothpick inserted in to the center of the cake only has a few moist crumbs stuck to it. Cool on rack. When cake is completely cook either remove from pan and frost, or frost directly in pan.



Blackberry Buttercream Frosting


2 cups fresh blackberries (if frozen, thaw before using)

1 cup (2 sticks) butter, at room temperature

6 cups confectioners sugar

1 teaspoon vanilla

pinch salt


Using a food processor or immersion blender, puree the blackberries. To remove the seeds, pour the puree in to a fine mesh strainer. Using a small rubber spatula, push the blackberry pulp through the sieve. Discard the seeds. You should have a bit more than 2/3 cup of seedless blackberry puree.


In the bowl of an electric mixer fitted with the paddle attachment, cream the butter and sugar. Reduce the speed to low and carefully add the confectioners sugar, and mix until combined. Add the blackberry puree, vanilla, and a pinch of salt, and continue beating until smooth.


note: this recipe makes more frosting than you’ll need for this cake – I wanted the frosting to have a strong blackberry flavor, so the extra puree meant a higher volume of frosting. Whatever you don’t use can be kept in the fridge for 4-5 days, or stored in the freezer for a few months.


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