A cake almost too beautiful to eat.
Add orange slices to boiling sugar mixture; reduce heat to low.
Gently simmer, turning occasionally, until slices start to turn translucent, about 25 minutes.
Credit:Victor Protasio; Food Stylist: Emily Nabors Hall; Prop Stylist: Prissy Lee Montiel
Preheat oven to 350F.
Spray a 9-inch square baking pan with baking spray.
Transfer butter to a large heatproof bowl; let cool 10 minutes.
Sift together flour, baking powder, and salt into a medium bowl.
Gradually whisk flour mixture into egg mixture until combined.
Reserve any remaining slices for another use.
Spread batter evenly over orange slices using a small spatula.
Gently tap pan on counter a few times to get rid of any large air bubbles.
Bake in preheated oven until a wooden pick inserted in center comes out clean, 30 to 35 minutes.
Remove cake from oven; prick all over using a fork.
Brush cake with 1/4 cup reserved syrup.
Let cake cool in pan on a wire rack 10 minutes.
Invert cake onto a serving plate; prick all over using a fork.
Generously brush top of cake with 1/4 cup reserved syrup; save any remaining syrup for another use.
Serve cake warm or at room temperature.
