Preheat oven to 350°F (175°C). Grease a 9-inch springform pan with butter or cooking spray and line the bottom with parchment paper.

Grind half of the pistachios in a food processor until they reach a fine meal consistency, pulsing for 30-45 seconds, being careful not to over-process.

In a large bowl, combine almond flour, ground pistachios, baking powder, and salt, whisking until evenly distributed.

In a separate bowl, beat eggs and sugar with an electric mixer on medium-high speed for 3-4 minutes until pale yellow, thick, and fluffy.

Add orange juice, orange zest, vanilla extract, and almond extract to egg mixture, beating on low speed just until combined.

Gently fold the dry mixture into the wet ingredients using a rubber spatula with a folding motion until no dry streaks remain.

Pour batter into prepared pan, smooth the top, then sprinkle remaining whole pistachios evenly across surface, pressing gently.

Bake for 40-45 minutes until golden brown, edges pull away from pan, and a toothpick comes out with moist crumbs.

Cool in pan on wire rack for 15 minutes, then release springform sides and let cool completely, about one hour.

Prepare glaze by whisking powdered sugar, orange juice, orange zest, and salt until smooth and pourable.

Drizzle glaze over cooled cake, allowing it to drip down sides naturally. Let set for 20 minutes before slicing.