1. Preheat oven to 350°F (175C). Line the bottom of a 9-inch (23cm) springform pan with a parchment paper and brush with a little bit of olive oil, dust with flour. Set aside.
2. In a bowl, stir flour, ground almond, salt and baking powder. Set aside.
3. In a bowl of a stand mixer or in bowl using a hand mixer, beat eggs and sugar on high speed for about 4-5 minutes, until light, pale and fluffy. While beating on low speed, slowly add olive oil, in steady stream until incorporated.
4. Add vanilla extract and orange zest, mix until combined. Add half of the orange juice, beat until combined, add half of the flour mixture, beat until combined. Add the remaining orange juice, beat, add the remaining flour mixture and beat until combined.
5. Pour batter into prepared pan. Bake for about 35 minutes, until a toothpick inserted in the center comes out clean.
6. Let cool, dust with powdered sugar before serving.