Olive oil is the secret to a very moist, tender cake - blueberries and almonds are a nutritional boost.
Grease side and bottom of a 9-inch springform pan with olive oil; dust with sugar. In mixer bowl, combine first 3 ingredients with 1/2 cup sugar. Combine buttermilk, olive oil and egg yolks. Add to dry ingredients; blend until smooth. Stir in orange zest and juice. In large mixer bowl, beat egg whites until soft peaks form (about 1 minute). Gradually add 1/4 cup sugar. Beat at high speed until stiff (about 2-3 minutes). Using a few strokes, whisk one half of cake batter into egg white mixture. Gently whisk in remaining cake batter until no white streaks remain. Pour into prepared pan. Toss blueberries with 1 teaspoon flour; scatter over batter. Sprinkle with almonds and 1 tablespoon sugar. Bake in a preheated 350 F oven until wooden pick inserted in center comes out clean (55-60 minutes). Cool 10 minutes; remove side from pan. Cool 5 minutes. Invert; remove bottom of pan. Invert again onto serving plate.