1. Prepare the Pan

• Preheat your oven to 350°F (175°C).
• Grease a 9-inch springform pan with butter, ensuring even coverage on the bottom and sides.
• Sprinkle a light layer of sugar inside the pan. Swirl it around to coat and tap out any excess. This helps form a light caramelized crust on the cake.

2. Zest and Slice the Blood Oranges

• Use a microplane grater to zest 2 teaspoons of zest from the blood oranges.
• Slice the top and bottom off each blood orange to expose the flesh.
• Stand each orange upright and carefully slice off the peel and white pith, working around the fruit with a sharp knife.
• Lay the peeled oranges on their sides and slice into thin rounds (about 1/4 inch thick). Set the slices aside for topping.

3. Mix the Dry Ingredients

• In a medium bowl, whisk together the all-purpose flour, almond flour, salt, and baking powder. This helps distribute the baking powder evenly.

4. Cream the Butter and Sugar

• In a large mixing bowl, use a stand mixer or electric hand beater to cream the butter and 3/4 cup sugar until pale and fluffy (about 5 minutes).
• Add the blood orange zest and scrape in the seeds from the vanilla bean (or add the vanilla extract). Mix to incorporate the flavors evenly.

5. Add Eggs and Lemon Juice

• Add the eggs one at a time, mixing well after each addition to ensure they are fully incorporated.
• Pour in the lemon juice and continue beating for about 4 minutes, until the mixture is pale and airy.

6. Combine Dry Ingredients and Yogurt

• With the mixer on low, gradually add the dry flour mixture to the batter, mixing just until combined.
• Add the Greek yogurt and stir until smooth. Avoid overmixing, as this could make the cake dense.

7. Assemble the Cake

• Spoon the batter into the prepared springform pan and smooth the top with a spatula.
• Arrange the blood orange slices over the batter in a decorative pattern, slightly overlapping them.
• Sprinkle the remaining 2 tablespoons of sugar evenly over the top, avoiding the very edges.

8. Bake the Cake

• Place the pan in the center of the oven and bake for 45 minutes to 1 hour.
• The cake is done when the edges are golden, the blood orange slices are caramelized, and the center is mostly set (a toothpick inserted should come out with a few moist crumbs).

9. Cool and Serve

• Allow the cake to cool completely in the pan before removing the sides.
• Slice and serve with dollops of Greek yogurt on the side. The cake tastes best when cold, so refrigerate it before serving if time allows.