Tell me how to make Upside-Down Ombré Citrus Cake.
Here's a recipe for Upside-Down Ombré Citrus Cake:

Ingredients:

• nonstick cooking spray, for greasing

Orange Syrup

• 3/4 stick unsalted butter
• 1 cup granulated sugar
• 1/4 cup fresh orange juice

Citrus

• 1 blood orange, thinly sliced
• 1 cara cara orange
• 1 navel orange, thinly sliced
• 1 meyer lemon, thinly sliced

Orange Vanilla Cake Batter

• 3 large eggs, room temperature
• 1 cup sour cream, room temperature
• 1/2 cup water
• 1/3 cup melted butter
• 1 navel orange, zested
• 1 navel orange
• 2 teaspoons vanilla extract
• 1 box vanilla cake mix
• 1 box instant vanilla pudding mix

Instructions:

1. Preheat the oven to 350°F (180°C). Generously grease an 8 x 11-inch baking dish with nonstick spray.
2. Make the orange syrup: Add the butter, sugar, and orange juice to a small saucepan. Whisk to combine, then cook over medium heat until the sugar dissolves, stirring occasionally to prevent burning, 4–5 minutes.
3. Pour the orange syrup into the prepared baking dish. Starting from a short side of the baking dish, arrange the blood orange slices vertically, overlapping slightly to fit as many slices as possible (this will help keep the citrus in place during baking). Continue with the cara cara slices, then navel orange slices, then Meyer lemon slices to create an ombré effect.
4. Make the cake batter: Add the eggs, sour cream, water, melted butter, orange zest and juice, and vanilla to a large bowl and whisk to combine. Add the cake mix and pudding mix and fold with a rubber spatula to incorporate. Pour the batter into the baking dish, spreading evenly.
5. Bake the cake for 45–50 minutes, or until a toothpick inserted into the center of the cake comes out clean.
6. Let the cake cool for 15 minutes, then invert onto a serving platter. Let cool completely before slicing and serving.

Enjoy your Upside-Down Ombré Citrus Cake!