Preheat your oven to 180°C (350°F). If using a convection oven, refer to note 4 for adjustments. Prepare two 8-inch round cake pans by greasing them thoroughly or lining them with parchment paper. For best results, you may use a homemade cake release.

Place the pistachios in a food processor and pulse until they are ground into fine crumbs. Be careful not to over-process them into a paste. Set these aside.

In a mixing bowl, sift together the flour, cornstarch, baking powder, baking soda, and salt. Whisk the dry ingredients thoroughly to ensure they are well combined and aerated. Reserve this mixture for later.

In a separate large bowl, combine the butter, vegetable oil, and sugar. Use an electric mixer, either handheld or stand-mounted, to cream the mixture on medium speed for approximately 2 minutes until it becomes pale and fluffy.

Add the eggs one at a time, beating for 10–15 seconds between each addition. Once the eggs are fully incorporated, mix in the vanilla extract, almond extract, vinegar, and half of the buttermilk. Set the mixer aside.

Using a spatula, gently fold half of the dry ingredients into the wet mixture until just incorporated. Then, stir in the remaining buttermilk, followed by the rest of the dry ingredients. Be careful to fold gently to avoid overmixing, which could affect the cake’s texture. Finally, fold in the ground pistachios and a small amount of green food coloring, if desired. Adjust the coloring to achieve a soft pastel hue.

Divide the batter evenly between the prepared pans. Bake for 40–45 minutes, or until a skewer inserted in the center comes out clean or with a few moist crumbs. Let the cakes cool in the pans for 15–20 minutes before transferring them to a wire rack to cool completely.

In a large bowl or the bowl of a stand mixer fitted with a paddle attachment, combine the butter, powdered sugar, vanilla extract, almond extract, and heavy cream. Begin mixing on the lowest speed to incorporate the ingredients, then increase the speed to medium-high. Beat the mixture for 10 minutes, stopping halfway to scrape down the sides of the bowl.

Add the cream cheese and ground pistachios to the frosting. Mix just until everything is evenly combined, taking care not to overmix, as this could affect the frosting’s texture. If you wish to add green food coloring, do so sparingly to achieve a soft pastel tone.

The frosting should have a silky, smooth consistency and be ready to spread or pipe onto the cooled cakes. For troubleshooting or decorating tips, refer to the recipe notes.