• Preheat the oven to 350℉. Grease and line an 8” cake pan with a parchment paper round to cover the bottom.
• Add the pistachios to a food processor and pulse until finely ground.
  ½ cup pistachios
• In a medium bowl, whisk together the dry ingredients. Set aside.
  1 ½ cups all-purpose flour, ¾ teaspoon baking powder, ¼ teaspoon baking soda, ¼ teaspoon kosher salt
• Rub the lemon zest into the sugar until pale yellow and fragrant. Then, add the butter and lemon sugar to the bowl of a stand mixer fitted with the paddle attachment (or use a handheld mixer). Cream together on medium speed for 3 minutes. Scrape down the sides.
  ¾ cups granulated sugar, Zest of 1 lemon, 6 tablespoons unsalted butter
• Add in the eggs and vanilla and mix on medium speed until pale in color and smooth, about 1 minute.
  1 large egg + 1 egg yolk , ½ tablespoon vanilla extract
• Add the buttermilk and mix on low speed, then spoon in the dry ingredients until the cake batter is combined.
  ½ cup buttermilk
• Fold in the ground pistachios by hand with a rubber spatula.
• Pour the batter into the prepared cake pan and bake for 25-30 mins until a toothpick inserted in the center comes out with a few moist crumbs but no wet batter.
• While the cake bakes, heat the sugar and lemon juice in a saucepan over medium heat until the sugar is dissolved. Remove from the heat.
  ⅓ cup lemon juice, ⅓ cup sugar
• When the cake is baked, brush or slowly pour the lemon syrup all over the top and sides of the cake (while hot).
• Cool the cake in the pan for 15 minutes, then remove and finish cooling on a wire rack.
• When the cake is fully cool, make the lemon mascarpone frosting.

Lemon Mascarpone Frosting

• In the bowl of a stand mixer fitted with the whisk attachment (or with a hand mixer), add the mascarpone, lemon zest, lemon juice, powdered sugar, honey and vanilla and whip on medium speed for 1 minute.
  8 oz mascarpone cheese, Zest of 1 lemon, 1 tablespoon fresh lemon juice, ¼ cup powdered sugar, 2 tablespoons honey, 1 teaspoon vanilla extract
• With the mixer running, slowly drizzle in the heavy cream and whip until the frosting becomes light and fluffy, about 1-2 minutes.
  1 cup heavy whipping cream
• Note: Overmixing can cause the frosting to curdle.
• Swoop the frosting all over the top of the cooled cake and sprinkle with chopped pistachios before slicing and serving.