Blood Orange Poppy-Seed Upside-Down Cake

1. Prepare the Pan and Preheat Oven

Preheat your oven to 350°F (180°C). Prepare your 9- or 10-inch cake pan by buttering it and lining the bottom with parchment paper.

2. Prepare Blood Oranges

Grate about 2 teaspoons of zest from the blood oranges and set it aside. Carefully slice or peel and segment the blood oranges. Arrange these slices neatly at the bottom of your prepared cake pan.

3. Cream Butter, Sugar, and Zest

In a stand mixer or with a sturdy spoon and bowl, mix together ½ cup of unsalted butter, 1 cup of granulated sugar, and the blood orange zest. Beat them until the mixture is light and fluffy, about 3 to 5 minutes.

4. Add Egg and Vanilla

Add 1 large egg and 1 tablespoon of vanilla extract to the creamed butter mixture and mix until well combined.

5. Combine Dry Ingredients

In a separate bowl, whisk together 1½ cups of all-purpose flour, ¾ teaspoon of baking powder, ½ teaspoon of baking soda, 3 tablespoons of poppy seeds, and 1 teaspoon of sea salt.

6. Mix Dry and Wet Ingredients

Alternately add the dry mixture and 1 cup of sour cream to the butter mixture, starting and ending with the dry ingredients. Mix on low speed, then finish by hand to prevent overmixing.

7. Bake the Cake

Spread the prepared batter over the orange slices in the cake pan. Smooth the top and bake in the oven for 45 to 55 minutes, until the cake springs back lightly when pressed.

8. Cool and Invert the Cake

After baking, let the cake cool in the pan on a wire rack for about 10 minutes. Then, carefully invert the cake onto a platter to reveal the beautiful blood orange top.