The Ultimate Orange Fluff cake: Prepare to be amazed!

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.