Chocolate Cake with Boysenberry + Raspberry Rose Buttercream Frosting

This Chocolate Cake with Boysenberry + Raspberry Rose Buttercream Frosting is outrageous! I made it over the weekend just for fun and it really was so much fun to make. There is something so rewarding about making a beautiful layer cake...

Ingredients

Chocolate Cake:2 cups / 400g caster sugar1 ¾ cups / 225g organic all purpose flour¾ cup / 75g cocoa powder (I used Dagoba)1 ½ teaspoons baking powderOne and a half teaspoons baking soda1 ¼ teaspoons rose salt or kosher salt1 cup / 240ml organic buttermilk (at room temperature)½ cup / 120ml organic grapeseed oil or canola oil⅓ cup / 75g full-fat organic plain yogurt (at room temperature)2 large eggs, room temperature (you an place in warm water for 10 minutes if you ever forget to pull your eggs out of the fridge early)2 teaspoons organic vanilla extract¾ cup / 180ml strong hot coffeeBoysenberry + Raspberry Rose Buttercream:8 ounces / 225g fresh boysenberries and raspberriesHalf dozen large egg whites1 ¼ cups / 250g caster sugarpinch of salt2 cups / 450g unsalted butter, soft but still cool1 teaspoon organic, edible dried rose petals, crushedGarnish:8 ounces / 225g fresh organic boysenberries + raspberriesFresh edible chamomile flowers or rose petals if you wish...

Directions:

First make the cake!

Preheat your oven to 350°F / 180° C. Place oven rack in the middle position of your oven. Butter three 8" cake pans lining the bottoms with parchment paper then butter the top of the parchment paper.Into the bowl of a stand mixer, sift all of the dry ingredients: sugar, flour, cocoa powder, baking powder, baking soda and salt. Mix until well combined.In a separate medium-sized bowl, whisk together all of the wet ingredients: buttermilk, oil, yogurt, eggs, and vanilla.Fit your stand mixer with a paddle attachment. Slowly pour the liquid mixture into the dry ingredients, keeping the speed on low. Once the ingredients begin to combine, stop the mixer and scrape down the sides and bottom of the bowl. Then increase to medium speed until the mixture has combined. On very low speed, slowly add the coffee until combined. The batter will be very thin.Distribute the batter evenly among the three cake pans and bake for 20-25 minutes or until a toothpick placed in the center of the cake comes out clean.Keep the cake layers in their pans and place on a cooling rack for 15 minutes. Invert and remove from pans and allow to cool on the cooling rack for about an hour before frosting.I made the cakes the day before using and after they were completely cooled, wrapped each layer in plastic wrap and placed in the fridge.

To make the Boysenberry + Raspberry Rose Buttercream Frosting:

Using either an immersion blender or a potato masher, smash the boysenberries and raspberries and then strain through a fine mesh sieve to remove all of the seeds.Fill a small saucepan with a few inches of water and bring to a simmer.Place egg whites and sugar in the bowl of a stand mixer. Place the bowl on top of the saucepan and whisk often for about 8-10 minutes until mixture becomes syrupy and is too hot to touch.Transfer the mixing bowl to the stand mixer. Add a pinch of salt. Using a whisk attachment, whisk until stiff peaks form and until the mixture has cooled, about 7-10 minutes.Switch to a paddle attachment.On a medium speed, add the butter 1 tablespoon at a time, until the butter is fully incorporated, scraping the bowl occasionally. Once the butter has been fully incorporated, slowly stream in the boysenberry and raspberry puree. Add rose petals. Mix until well blended and fluffy.Once the cake layers have cooled completely, you can begin to frost. Place one layer on a cake stand and add about 3/4 cup of frosting. Add a few fresh berries to the top of the frosting, then place the middle layer on top. Continue this process until you reach the top layer. Add a light layer of frosting to the top and the sides, then place the cake in the fridge for 30 minutes to cool slightly. Remove the cake from the fridge and add one more layer of frosting to cover the entire cake. Pile fresh berries on top of the cake and garnish with fresh chamomile flowers or rose petals.This cake can be kept in the fridge for 4 days. Serve at room temperature.{SHOP} Sweater, Earrings, Scarf (vintage similar linked), Cake Stand (old similar linked), Floral Plate, Measuring cup/pitcherPhotography by Nicholas Winslow + Cassie WinslowRecipe adapted from Yossi Arefi's delightful cookbook, Sweeter off the Vine