Angel cakes don't use any yolks.
SPONGE CAKE
6 eggs
1 TBL lemon juice
1 tsp grated lemon rind (no white part, only the yellow)
1 cup sifted cake flour
Pinch of salt
1 cup sugar

Preheat oven to 325°. Lightly grease & flour the bottom, not the sides of a 10" tube pan.
Break the eggs into the large bowl of a mixer, add the lemon juice & grated rind & beat the mixture at highest speed until soft peaks form, 12-16 minutes.
while the eggs are being beaten, sift together the flour & salt onto a piece of waxed paper.
Continue beating the eggs at highest speed (after soft peaks form) & pour the sugar in a fine stream over them, taking 2 1/2 to 3 minutes to add all the sugar.
Change to lowest speed & sift the flour & salt over the surface of the mixture as the bowl turns, taking 2 1/2 to 3 minutes to add all the flour. Scrape the sides of the bowl & beat at lowest speed 1/2 minutes.
Pour the batter into the prepared pan & bake 50 minutes, or until a toothpick inserted near the center comes out clean.
Invert the cake pan & set it on a rack to cool. Prop it up if necessary so that the air can circulate between the cake & countertop. Let the cake cool at room temperature before removing it from the pan.~~from Craig Claiborne

Oh, forgot about this: the flan you're talking about is sort of like a tart with fruit. The other type is the custard kind.

The sponge cake you want is a "jelly roll" cake.

INGREDIENTS:

3/4 cup cake flour
3/4 teaspoon baking powder
1/4 teaspoon salt
4 eggs
3/4 cup sifted sugar
1 teaspoon vanilla extract
PREPARATION:

Sift flour once, then measure. Combine baking powder, salt, and eggs in a bowl. Place bowl over a pan or bowl of hot water then beat with an electric mixer until egg mixture is thick and light lemon-colored

Remove bowl from the pan or bowl of hot water. Fold in flour and vanilla. Line a 15x10x1-inch jelly roll pan with greased wax paper or parchment paper. Spread batter in prepared pan; bake at 400° for 13 minutes or until just done. The center should spring back when lightly touched. Quickly trim crisp edges from cake. Turn out onto a clean dish towel which has beef liberally sprinkled with confectioners' sugar. Peel paper from bottom of cake.

The "flan pan" it calls for is also known as a tart tin....it's a shallow fluted edge pan, often with a removable bottom.

An algelfood cake is make with only egg whites and I don't believe it would work to bake it in a shallow pan.
Linda C

Linda C, when do you add the sugar? At the beginning with the eggs over the hot water?

Thanks. Carmellia