Tres Leches Cake

Let the first 3 egg whites, the egg yolks and the 1/4 cup milk stand at room temperature for 30 minutes. In a medium bowl combine flour and baking powder; set aside. Grease 9x9x2-inch baking pan; set aside.
In a large mixing bowl combine the egg whites and cream of tartar. Beat on medium speed of an electric mixer until soft peaks form; gradually add 1 cup sugar while beating on high speed. Beat in egg yolks, 1 at a time, beating well after each addition. On low speed, beat in flour mixture 1/4 at a time. Beat in 1/4 cup milk just until combined. Pour into prepared pan.
Bake in a350 degree oven for 25 to 30 minutes of until a toothpick inserted into the center comes out and top springs back when lightly touchedt Let cool on a wire rack.
Combine whipping cream, sweetened condensed milk, and evaporated milk. With a tooth pick, poke holes in top of cake at 1 inch intervals. Pour milk evenly over top. Cover and refrigerate over night.
For topper, in a large heat proof bowl, combine corn syrup and remaining 2 egg whites. Bring 1 inch of water to a simmer in a very large skillet. Place the bowl in the skillet of simmering water. Beating constantly with a hand-held electric mixer, beat 2-3 minutes or until temperature registers 140 degrees on an instant-read candy thermometer. Continue beating over hot water for 5 minutes. Carefully remove bowl from pan. Beat 2-3 minutes longer or until cool. Spoon atop cake. Serve within 2 hours. When cut milk seeps out and pools around cake.