Preheat your oven to 350°F. Thoroughly grease a 9-inch bundt cake pan, ensuring you coat all the sides of the bowl.
In a large mixing bowl or bowl of a stand mixer, cream together room temperature butter and sugar at medium speed until light and fluffy, about 3 minutes.
Add eggs one at a time at low speed, scraping down the sides of the bowl between additions.
In a medium bowl, combine flour and baking powder. Soak nuts briefly, then toss with the dry ingredients, reserving some pistachios for garnish.
Gradually fold the flour mixture into the wet ingredients until just combined.
Pour the batter into your prepared pan and bake for approximately 40 minutes or until a tester comes out clean.
Notes
Grease your bundt pan thoroughly with nonstick spray or use a pastry brush with melted butter for easy release
Bring all refrigerated ingredients to room temperature for the best results
Don't overmix the batter once you add the flour to ensure a tender crumb
Let the cake cool in the pan for 10 minutes before turning out onto a wire rack