Preheat the oven to 350 degrees. Spray a 9×9 pan with non-stick spray and line it with parchment paper.

Add the pistachios to a food processor and pulse until finely ground.

In a medium bowl, whisk together the all purpose flour, baking powder, baking soda, and salt. Then set aside the flour mixture.

Add the softened butter and granulated white sugar to a large bowl. Cream together for 2 minutes with an electric mixer.

Then add in the eggs and vanilla and mix on medium speed until pale in color and smooth, about 1 minute.

Add the buttermilk and the dry ingredients to the wet ingredients a little at a time and mix on low speed until the cake batter is combined.

Fold in the ground pistachios.

Pour the batter into the prepared baking pan.

Bake the cake for 38-44 minutes, or until a cake tester comes out clean from the center.

Then let the cake cool in the pan on a wire rack until completely cool.

Add the butter to a large mixing bowl and mix on high speed with an electric mixer until pale and fluffy, about 5 minutes.

Then add in the cream cheese and mix on high speed until fluffy, about 1 minute.

Sift in the powdered sugar and mix on low speed until combined. Then mix on high speed until fluffy again.

Grind the pistachios in a food processor until they turn into pistachio butter.

Add the pistachio butter and sweetened condensed milk to a bowl and whisk to combine.

Add the heavy cream to medium bowl and beat it with an electric mixer on high speed until firm peaks form.

Fold the whipped cream into the pistachio mixture. Transfer to a piping bag until ready to use.

When the cake is completely cooled carefully turn the pan over to release the cake. Transfer it to a serving plate. Poke holes on the top of the cake using a wooden stick or the handle of a wooden spoon.

Pipe the pistachio cream into the holes of the cake.

Frost the top of the cake with a thick layer of cream cheese frosting. Swirl pistachio cream into the frosting and sprinkle with chopped pistachios. Then serve!