PISTACHIO TIRAMISU SPONGE CAKE

Notes: My recipe for pistachio tiramisu sponge cake incorporates fresh roasted, ground pistachios in the cake itself as well as roasted pistachios processed all the way to a smooth, creamy butter in the mascarpone cream. There’s a reason why tiramisu is usually made as a dessert in a container or dish rather than as a cake. Lady fingers soaked in espresso and soft mascarpone cream don’t hold their shape well unless layered and chilled for several hours. So to make pistachio tiramisu as a cake and keep everything spongy, pliable and creamy was a challenge. My pistachio sponge cake is very soft and eggy and soaks up the coffee liqueur as you would expect. I think once you try this recipe you’ll wonder why tiramisu is ever made without pistachio. I made this cake 6 times while developing this recipe and I still can’t get enough.

Use a firm mascarpone cheese, but be careful when whipping with the cream and pistachio. Certain brands are easy to overwhip and you’ll end with a “curdy” cream. If you use a soft mascarpone, the cream will taste amazing, but make for a messy looking cake as the whipped mascarpone and pistachio cream will be very soft.

As usual, ingredients where listed in grams were weighed.

Total time: 3.5-4 hours

Special Equipment:

• Digital kitchen scale

  This is the one I use and love: OXO Good Grips 11-Pound Stainless Steel Food Scale

• Food processor (for pistachio flour and butter)

• Stand mixer (preferred for sponge cake)

• Electric hand mixer (optional)

• 8 inch cake pan

• Cooling rack

• Sieve (for sifting flour)

• Fine mesh sieve (for cocoa powder)

• Cake turntable (optional)

  This makes frosting cakes so much easier. This is the exact one I have and use: Kootek Aluminium Cake Turntable Set, Baking Tools with Revolving 12" Cake Stand for Decorating

Ingredients:

Pistachio flour and butter:

• 260g (2 cups) Raw, shelled pistacchios

• 3/4 tsp salt, or to taste (I used sea salt)

Pistachio sponge cake:

• 4 Eggs at room temperature

• 136 g (2/3 cup) Granulated sugar

• 2 tsp Vanilla extract

• 30 g (2 tablespoons) buttermilk, room temp

• 45 g (1/4 cup) Vegetable oil

• 85 g (~3/4cup) AP flour

• 50 g pistachio "flour"

• 1/2 tsp salt (I used pink Himalayan)

• 1/2 tsp baking soda

• 1/2 cup (120 mL) cold espresso or strong coffee.

  I used 2 tbsp of instant coffee crystals, to make it extra strong, from a brand that I like: Mount Hagen Instant Organic Coffee Crystals

• 1 tbsp brandy or coffee liqueur (optional)

• Cocoa powder (for dusting)

Pistachio Mascarpone cream:

• 1.5 cups (360 mL) cold heavy whipping cream

• 115 g (4oz) pistachio butter

• 227 g (8oz) firm mascarpone cheese, room temp

• 45 g (1/2 cup) powdered sugar

• 2 tsp vanilla extract

• Pinch of salt, to taste

Directions:

Pistachio flour and butter:

1. Preheat oven to 350 F.

2. Spread your raw pistacchios across a large parchment lined (or silicone mat lined) baking sheet and toast them in the oven until fragrant (~8-10 mins).

3. Let the pistacchios cool for at least 10 mins.

4. Food process (I recommend using pulse so you don't go too long by accident) the pistachios until you have a meal or flour (looks like almond flour but green), about 1 min. Remove 50 g from the food processor (you will use this in the sponge cake).

5. Process the remaining pistacchio meal in the food processor and keep going until you have a smooth, creamy, glossy butter. Pause to scrape down the sides as needed and add salt about half way through. The pistacchios will go from a clumpy meal, to a cohesive ball, and finally to a smooth, glossy butter. This process will take several minutes so you can stop for a few mins if your food processor gets too hot.

6. Let the pistachio butter cool to room temperature. You will use 115 g of this in the mascarpone cream and have some left over. Transfer the remainder to a relatively airtight container or jar. The butter keeps well at room temperature for a couple weeks, but even longer in the fridge.

Pistachio sponge cake:

1. Keep oven on 350 F from previous step and bring all the cake ingredients to room temperature.

2. Prepare an 8 inch cake pan with parchment paper (oil the bottom and sides and cut parchment paper to fit and it will adhere to the oil). 

3. In a mixing bowl, whip together the eggs, vanilla extract, salt and sugar with a stand mixer for at least 5 minutes at high speed until very pale, creamy, and fluffy. We are going after the so-called ribbon stage, where the eggs and sugar mixture is whipped until it's thick and several shades lighter and falls like a "ribbon" when you lift the whisk.

4. Next, reduce the mixer to a lower speed and continue whipping for another 1-2 minutes. This helps break larger air bubbles preventing large holes in your sponge cake.

5. Sift in the AP flour, and add pistachio “flour” and baking soda and then gently fold into the egg mixture with a rubber spatula, until JUST combined, being careful not to deflate the batter (a couple visible streaks of flour is ok). However, the pistachio flour is heavy and will sink to the bottom of the bowl so make sure your spatula is scraping the bottom of the bowl as you fold.

6. Then, pour in the room temperature buttermilk and oil and mix it with "cut and fold" movements just until just incorporated.

7. Pour the sponge cake batter into your prepared pan and bake at 350 F  for 28-30. Do not open the oven door in the first 28 minutes. At 28 mins you can check the cake (toothpick inserted comes out clean). My oven is exactly 350 F internally when the temp is set so I baked mine for 30 mins. Flip the cake pan upside down and let the sponge cake cool completely on a wire rack (it should slip right out of the pan with no effort). Once the sponge cake cools to room temperature, you can cut in half horizontally.

Pistachio mascarpone cream:

1. Add mascarpone cheese, pistachio butter, vanilla extract(and optional almond extract to a mixing bowl (or stand mixer bowl), Whip until creamy and slightly aerated (a couple mins).

2. Add powdered sugar and beat to combine. With the mixer on medium speed, gradually add the heavy whipping cream to the mixture, beating to incorporate.

3. Once all cream has been added, increase the speed to medium-high for 1-3 minutes until stiff peaks form and it's the consistency of a fluffy frosting. *Be careful whipping in this last step. I have found that firm mascarpone mixed with cream and pistachio butter can be easily over whipped and form curds.

4. Chill the pistachio mascarpone cream for at least 30 mins before using.

Tiramisu Assembly:

1. Drizzle 1/4 cup of the espresso (or coffee) with optional brandy on the first layer of your sponge cake (which has been cut in half). Flip the top half of the sponge cake over (crumb side up) and pour the remaining coffee on there.

2. Smooth about a third of the pistachio mascarpone cream over the top of the first layer.

3. Place the second layer of sponge on top (crumb side down), and smooth remaining pistachio mascarpone cream over the top and sides.

4. Generously dust cocoa powder over the top using a fine mesh sieve.

5. Refrigerate for at least 1 hr. Chilling for several hours or overnight works great too so feel free to make this the day before you serve it.

6. Garnish with optional sliced strawberries (rasberries would be good too) before serving. This cake stays soft and delicious in the fridge for days.