Cake1 tablespoon unsalted butter, at room temperature
2 cups all-purpose flour plus 1 tablespoon for the pan
½ teaspoon saffron threads
2 tablespoons fresh orange zest
2 tablespoons orange juice
1 cup shelled, unsalted pistachios, finely ground in a food processor
1 teaspoon baking powder
¾ teaspoon kosher salt
4 large eggs
1 cup granulated sugar
1 cup extra-virgin olive oil
1 teaspoon vanilla extract
Candied Pistachios½ cup whole, shelled unsalted pistachios
¼ cup granulated sugar
2 teaspoons finely grated orange zest
2 tablespoons water
¼ teaspoon sea salt
Glaze1¾ cups confectioners' sugar
2½ tablespoons fresh orange juice
Directions
Preheat the oven to 350°. Coat a 9-inch-by-5-inch loaf pan with 1 tablespoon butter, then add 1 tablespoon flour to the pan, tap out the excess and set aside.
Make the cake: In a small saucepan set over medium heat, combine the saffron with the orange zest and juice. Bring to a simmer, turn off the heat and set aside. In a medium bowl, whisk together the ground pistachios, the remaining 2 cups of flour, baking powder and salt. Set aside.
In a standing mixer, whisk together the eggs and sugar on medium speed until smooth. Gradually beat in the olive oil until the egg-sugar mixture is creamy, about 2 minutes. Whisk in the reserved orange-saffron mixture and the vanilla extract. Reduce the speed to medium-low and gradually add the dry ingredients to the egg mixture until just combined. Pour the batter into the prepared loaf pan and bake until a toothpick inserted in the center comes out clean, 1 to 1½ hours. Cool the cake in the pan for 10 minutes, then invert on a cooling rack and cool completely.
While the cake cools, make the candied pistachios: Line a rimmed baking sheet with parchment paper or use a silicone mat. In a medium saucepan, combine the whole pistachios, sugar, orange zest, water and sea salt. Set over medium heat until the sugar dissolves and the liquid evaporates, 7 to 10 minutes, stirring occasionally. Pour the candied pistachios onto the prepared baking sheet and let cool completely. Pulverize in a food processor until coarsely ground. Set aside.
Make the glaze: In a medium bowl, whisk together the confectioners' sugar and orange juice until smooth. Drizzle the glaze over the olive oil cake and sprinkle with candied pistachios. Slice and serve.