Rhubarb Upside-Down Cake - corn syrup

Method

• TO PREPARE TOPPING: Coat a 10-inch ovenproof skillet (such as castiron) with cooking spray.
• Add corn syrup and butter; heat over low heat until butter has melted, swirling the pan to coat the bottom evenly.
• Remove from the heat; spread the brown sugar evenly over the bottom of the pan.
• Sprinkle the nuts over the sugar and arrange the rhubarb, rounded side down, in a circular pattern on top.
• Set aside.
• TO PREPARE CAKE: Preheat oven to 375F Combine flour nuts, baking powder and salt in a food processor or blender; process until finely ground.
• Beat two egg whites in large bowl with an electric mixer on high speed until soft peaks form.
• Gradually add 1/3 cup brown sugar, beating until stiff and glossy.
• Set aside.
• (It is not necessary to wash beaters).
• Beat whole eggs with the remaining 1/3 cup brown sugar in another large bowl on high speed until thickened and pale, 3-5 minutes.
• Blend in orange zest and vanilla.
• Whisk one-fourth of the beaten whites into the whole egg mixture.
• Gently fold in half the flour mixture.
• Fold in the remaining beaten whites, followed by the remaining flour mixture.
• Spread the batter evenly over the rhubarb.
• Bake the cake until the top springs back when touched lightly, 25-30 minutes.
• Let cool in the pan on a wire rack for 5 minutes.
• Loosen the edges with a knife.
• Invert a serving platter over the cake.
• Using oven mitts, grasp platter and skillet together and carefully flip them over.
• Let the skillet sit for a few minutes to allow any caramel clinging to it drip onto the cake.
• Remove the skillet.
• Let the cake cool at least 20 minutes.
• Serve warm or at room temperature.