Step 1

For timing purposes, I recommend you start with the raspberry filling to let it chill, then make the pistachio butter if you aren't buying it, then make the pistachio cake, and while the cakes are cooling, make the buttercream.

Step 2

First, combine the raspberries and sugar in a saucepan and bring them to a boil.

Step 3

Then, use an immersion blender to make the filling smooth (or leave it chunky if you prefer).

Step 4

In a separate container, combine your Clear Jel (or cornstarch) and water to make a slurry.

Step 5

Then, pour it into the raspberry mixture and let it simmer until the mixture is clear and thickened.

Step 6

Remove the raspberry filling from heat, and then stir in the lemon juice and zest.

Step 7

Pour the filling into a heatproof bowl and cover with plastic wrap so it’s touching the surface of the filling to prevent skin from forming.

Step 8

Finally, cool the raspberry filling entirely before using it. Store any leftovers in the fridge for up to a week or in the freezer for up to 6 months.

Step 9

Prepare three 6” round cake pans with cake goop or another preferred pan spray.

Step 10

Preheat your oven to 335ºF (168ºC).

Step 11

First, in the bowl of your stand mixer, combine the dry ingredients. This includes flour, sugar, brown sugar, salt, baking soda, and baking powder. Mix them to combine.

Step 12

Then, in a separate bowl, combine the room temperature eggs, buttermilk, and vanilla. Whisk gently to combine and set aside.

Step 13

Next, using a large measuring cup, combine the oil and the pistachio butter. It is ok if these don’t completely mix together. Ultimately, the mixer will do most of the work for you.

Step 14

In the bowl of your stand mixer, add in the buttermilk/egg mix to the dry ingredients while mixing on low speed.

Step 15

Once it has evenly combined into the dry ingredients and thoroughly moistened it, add in the oil and pistachio butter.

Step 16

Mix your cake batter on medium speed until the batter is fully incorporated and smooth. Scrape the bowl to ensure that all of the ingredients are combined.

Step 17

Next, add in your desired amount of green food coloring to achieve the “pistachio color” you are wanting. I use one drop of avocado green. When you bake the batter, it will be slightly green but it tends to look more yellow if you do not use any green food coloring.

Step 18

Divide the cake batter evenly into your prepared cake pans, and bake them at 335ºF (168ºC) for 30-35 minutes or until a toothpick comes out from the center cleanly. Add 5 more minutes at a time until the cake is finished baking.

Step 19

Finally, cool your cakes for 10 minutes inside the cake pans before attempting to remove them from their pans onto a cooling rack. Freeze them for 1 hour before frosting.

Step 20

In the bowl of your stand mixer, combine the eggs and salt and whisk them until the yolks and whites are combined.

Step 21

Then, add in your sugar and whisk it to combine.

Step 22

Next, place the bowl over a water bath of simmering water over medium heat.

Step 23

Whisking occasionally, heat the eggs and sugar until the sugar is dissolved. It should feel smooth when you rub it together with your fingers.

Step 24

Periodically stir the eggs and watch them to ensure they do not heat unevenly. If you don’t occasionally stir and watch the eggs, they will likely cook on the side of the bowl. Another thing to look out for is the sugar can sink to the bottom of the bowl causing uneven heating.

Step 25

Store bought eggs come pre-pasteurized, so heating them to a particular temperature is unnecessary. However, you must have the sugar dissolved for the meringue to whip properly.

Step 26

Then, once the eggs and sugar are ready, move the bowl to your mixer and begin to whip them at high speed using your whip attachment.

Step 27

After about 5-8 minutes, the meringue will almost double in size and form into firm (but not stiff) peaks. FYI: The addition of the egg yolks will keep the meringue from becoming stiff like an all-white meringue.

Step 28

Once the meringue has cooled (feel the bowl with your hand), begin to add in your butter in chunks while mixing on low.

Step 29

Then, after you add in all of your butter, whip the buttercream a few more minutes until the texture changes to a whipped cream-like texture. Once you have the right consistency, add in your vanilla extract.

Step 30

Stop whipping the buttercream when it does not have a strong butter flavor anymore, and it is light and creamy in texture.

Step 31

While the paddle is mixing, add 2 oz of pistachio butter, and 1-2 drops of green food color to reach your desired color. Allow to mix on low to combine completely. Next, switch to your paddle attachment on your stand mixer and allow the meringue to paddle on low for 8-10 minutes. Ultimately, this will push out the air bubbles to get you the most desirable texture.

Step 32

Finally, prepare a piping bag to use your buttercream, or wrap it up and refrigerate it until you are ready to use it (or store it in the freezer as you would with Swiss meringue buttercream).

Step 33

First, trim off the dome of your cake layers and the brown edges around the sides and bottom.

Step 34

Place the first cake layer onto your cardboard cake round. Then, spread a thin layer of raspberry filling on top of the cake.

Step 35

Next, spread on about 1/4″ of your buttercream, and then add your next layer of cake.

Step 36

Repeat this process with layer two, and then add your final layer of cake on top.

Step 37

Cover the entire cake in a thin layer of buttercream. This is called the “crumb coat.”

Step 38

Then, place your cake into the fridge or freezer for 20 minutes to set the buttercream layer.

Step 39

Apply your final coat of buttercream and smooth out any edges you don’t like.

Step 40

Next, with clean hands, scoop up a handful of chopped up pistachios and carefully press them into the buttercream around the bottom of your cake.

Step 41

Sprinkle more chopped up pistachios on top of the cake in a circle around the edge.

Step 42

Finally, as an optional step, pipe a few dollops of buttercream using a piping bag and then place a few fresh raspberries on top. The reason you want to include pistachios and raspberries into your cake decoration is because you want someone to look at the cake and know what’s inside of it without having to cut into it!