This recipe is adapted from Good Housekeeping
4 Tangerines or 3 large oranges
2 1/4 Cups of cake flour
1 Tbsp baking powder
3/4 Tsp salt
1 1/2 Cup granulated sugar
5 Large eggs (separated)
2 Large egg whites
1/2 Tsp cream of tartar
2 Tangerines or 1 large orange
1 1/2 Cups of confectioners sugar
1/4 Tsp vanilla extract
Preheat oven to 325 F. Grate 1 Tbsp of zest from tangerines and squeeze 3/4 cup of juice. In a large bowl stir baking powder, flour, salt and 1 cup of sugar. Make a well in the center and add oil, egg yolks, tangerine zest and juice. Whisk into dry ingredients.
In another large bowl, with a mixer on high, beat 7 egg whites with cream of tartar until soft peaks form. Gradually sprinkle in remaining 1/2 cup of granulated sugar a little at a time and beat until whites stand in stiff peaks when the beaters are removed. Use a rubber spatula to gently fold 1/3 of the whites into the egg-yolk mixture to loosen the batter, then fold in the remaining whites.
Pour batter into ungreased 10-inch angel food cake pan. Bake 60 – 65 minutes or until the top springs back when touched gently. Invert cake pan on a metal funnel or bottle; cool thoroughly for an hour or two. With a knife, carefully loosen cake from the pan on both the side and the center. Remove cake from the pan and place on a plate.
Prepare glaze by grating 1 Tsp of zest and 2 and 1/2 Tbsp of juice. In a small bowl stir together confectioners sugar, vanilla, tangerine zest and 2 Tbsp of tangerine juice until smooth. Add remaining juice if necessary to get a nice smooth texture for spreading. Spoon glaze over cooled cake, spreading with a spatula and allow glaze to run down the sides. Let stand until the glaze is set which is about 30 min.