Preheat your oven to 350°F (175°C). Prepare an 8-inch round cake pan by lightly greasing the sides and lining the bottom with parchment paper.

In a food processor, pulse the shelled pistachios until finely ground, being careful not to over-process them into a paste. In a medium mixing bowl, whisk together the ground pistachios, all-purpose flour, baking powder, baking soda, and salt.

In a large bowl, cream the softened butter and granulated sugar together using a hand mixer until light and fluffy, which takes about 3 minutes. Beat in the eggs one at a time until fully incorporated, then stir in the vanilla and almond extracts.

Gradually add the dry pistachio mixture to the wet ingredients, alternating with the buttermilk in two additions. Mix gently with a spatula just until combined, ensuring there are no dry pockets of flour remaining.

Pour the batter into your prepared cake pan and smooth the top into an even layer with a spatula. Bake for 35 to 40 minutes, or until a toothpick inserted into the center comes out clean and the edges are golden brown.

Allow the cake to cool in the pan for 10 minutes before carefully turning it out onto a wire rack to cool completely. While the cake cools, whisk the powdered sugar and milk together in a small bowl until you have a smooth, pourable glaze.

Once the cake has cooled entirely, drizzle the sweet glaze evenly over the top, letting it gently drip down the sides. Garnish with a few extra chopped pistachios and serve slices alongside a hot cup of coffee or tea.