Orange Fluff Cake

Instructions

• Position a rack in the center of the oven and preheat to 350 degrees F (175 degrees C). Have ready an ungreased 10-inch tube pan with a removable bottom. Don't use a nonstick surface pan.
• Prepare the cake: Sift flour, 1/2 cup sugar, baking powder, and salt into a medium bowl. Form a well in the center and add melted butter, orange juice, orange zest, egg yolks, and vanilla. Beat for 1 to 2 minutes with an electric mixer.
• Beat egg whites and cream of tartar in a large glass or metal mixing bowl until foamy. Gradually add remaining 1/2 cup sugar, continuing to beat until stiff peaks form. Fold 1/3 of the whites into the batter, then quickly fold in remaining whites until no streaks remain.
• Pour batter into the ungreased tube pan. Bake in the preheated oven until the top springs back when lightly touched and a toothpick inserted comes out clean, 60 to 75 minutes. Immediately invert and let the cake hang upside down until completely cool.
• Turn right side up and run a sharp knife around the edge to separate the cake from the pan. Remove sides. Run a knife around the center tube and under the cake; remove the pan bottom. Place the cake right side up on a serving plate.
• Make the glaze: Combine confectioners' sugar, orange juice, and orange zest in a small bowl. Spread over the top of the cake, letting some drip down the sides. Let stand at room temperature until glaze has set, about 1 hour.