4 eggs, separated
zest of 1 lemon
zest of 1 orange
1 Tbsp. lemon juice
1 Tbsp. orange juice
½ cup sugar, divided
¼ tsp. cardamom
1 2/3 cup almond flour
1 tsp. baking powder
1 tsp. vinegar
pinch of salt
½ cup slivered almonds
Preheat oven to 350 degrees. Spray bottom and sides a 9-inch springform pan with cooking spray. Whisk egg yolks, citrus zests and juices and ¼ cup sugar in a small bowl. In a separate bowl whisk together almond flour, baking powder and cardamom. Add egg/citrus mixture, stirring to combine.
In a separate bowl, beat egg whites until foamy. Add salt and vinegar. Beat another minute and add remaining ¼ cup sugar. Beat to soft peaks.
Fold 1/3 of egg whites into almond flour batter. Gently fold in remaining whites. Spoon batter into prepared pan, sprinkle with slivered almonds and bake for 35 minutes. Cool completely and dust with powdered sugar. Makes 8-10 servings.