Start by preheating your oven to 350F/177C. Line three, 8-inch (20-cm) cake pans with parchment paper and spray the sides with anon-stick baking spray.
In a large mixing bowl, combine the sour cream, honey, cooking oil, eggs and vanilla extract. Beat this mixture for a few minutes, until it’s smooth and uniform. In a separate mixing bowl, combine the dry ingredients: flour, baking soda, baking powder and salt. Sift these dry ingredients into the cake batter, then mix for about 1 minute, just until incorporated.
Divide the prepared cake batter between the three pans. I like to use a kitchen scale to make sure each pan has the same amount of batter. Bake the cake layers in the preheated oven at 350F for 24 to26 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake layers to cool in the pans for about 5 to 8 minutes, then carefully take them out of the pans and onto a wire rack to cool completely. Once the cake layers have cooled, place them into the refrigerator to chill for about 30 minutes. This will make the layers less fragile.
Making Pistachio Buttercream:
Meanwhile, prepare a batch of my pistachio buttercream frosting. Keep the frosting refrigerated until you’re ready to use it!
Prepare the pistachio paste first. Place the shelled pistachios into a food processor, or a blender, and pulse until the pistachios are very well ground. Add in the heavy cream and pulse again until a thick paste forms. Set this paste aside.
Soften the butter at room temperature until it’s lightly softened. Place the butter into a mixer bowl and attach a flat beater. Beat the butter on medium to high speed for 7 to 9 minutes, until the butter is fluffy and white in color. Scrap down the sides of the mixing bowl often to ensure all the butter is well mixed.
Add in the pistachio paste and vanilla extract next. Beat for a few minutes, scraping down the sides of the mixing bowl, until the butter and pistachio paste are well combined.
Add the confectioner’s sugar next. Mix on low speed for, until the sugar is incorporated. Continue to beat on high speed for3 to 4 minutes, until the buttercream is light and fluffy.
If your buttercream is flat and doesn’t become fluffy, place it into the refrigerator to chill for 30 minutes. Once chilled, beat the frosting again until it’s fluffy. Keep the frosting refrigerated until you’re ready to use it.
Assembling the Cake:
To assemble the cake, first level the top of each cake layer, then split the layers in half. You should have 6 cake layers total. Drizzle about 2 tablespoons of honey onto the cake layer first and spread it with an offset spatula.
Add a generous amount of frosting onto the cake layer and spread it evenly to the edges. Transfer about a cup of the frosting into a pastry bag tipped with a medium-sized round tip. Pipe a barrier ring around the edge of cake, then sprinkle 3 to 4 tablespoons of the diced pistachios in an even layer on the inside. Drizzle a few more tablespoons of honey over the top, then add the next cake layer. Repeat this process for the remaining cake layers.
Next, apply a crumb coat of frosting on the outside to seal in the crumbs. Refrigerate the cake for about 30 minutes, to allow the frosting to set. Once chilled, add on the final layer of frosting and smooth it out with offset spatulas and cake spatulas. Watch my video tutorial to see how I do it.
To garnish the top, sprinkle more finely diced pistachios over the top of the cake and drizzle with a few tablespoons of honey. Transfer the remaining buttercream into a pastry bag; I used a French star tip #4. Pipe dollops onto the top to garnish the cake.
Serving & Storing the Cake:
Once you have the cake assembled and completed, I recommend placing it into the refrigerator for an hour or two, to allow the frosting to set. You can also leave the cake in the refrigerator overnight to chill. I recommend removing it from the refrigerator about an hour before serving, to allow the cake to soften. Since this cake is quite sweet, I recommend serving it with hot tea to break up the sweetness!
This honey cake with pistachios is on the sweet side, thanks to all the honey I add! I love to enjoy it with tea to help break up the sweetness. However, you can make this cake less sweet by reducing the amount of honey you add into the cake batter (from 1 cup to ¾ cup) and as a filling (reduce in half).