Preheat oven to 350º F. for metal and glass pan(s) 325º F. for dark or coated pan(s).

Making topping: Melt 1/4 cup butter in a 10-inch x 2-inch deep round baking pan. Remove pan from oven, sprinkle dark brown sugar over butter. Drizzle 2 tablespoons blood orange juice over brown sugar/ butter mixture. Lay blood orange slice on top of brown sugar/butter/ juice mixture. Sprinkle 1 teaspoon blood orange zest over blood orange slices, set aside.

Make cake: blend cake mix, blood orange juice, softened butter and eggs in a large bowl at low speed until moistened, about 30 seconds.

Beat at medium for 4 minutes. Stir in 1 teaspoon orange zest.

Carefully pour the batter into prepared pan, over the orange slices.

Evenly spread the batter over the top.

Bake for 45 minutes.

Remove from oven and let the cake rest for 5 minutes in the pan. Run a knife around the edges. Invert onto a cooling rack and tap lightly to release cake.

Serve cake warm with whipped cream.

Store cake in refrigerator.