Arrange rack in the middle of the oven, and heat the oven to 350F. Grease an 8-by-4-inch loaf pan with butter and sprinkle with cornstarch for easy removal.
Cut one blood orange and the lemon in half and zest all the skin.
Using the other half of the blood orange, slice thin slices for decorative topping and set aside.
Juice the remaining whole blood orange and the half of the lemon and set juice aside.
In a mixing bowl, combine the flour, baking powder, baking soda, and salt.
In a separate bowl whisk the citrus juice with the sugar, then add the eggs, extra virgin olive oil, yogurt, citrus zest and vanilla extract and whisk together.
Carefully fold the flour mixture into the wet ingredients mixture until fully combined but not over mixed.
Spoon the batter into the pan and arrange the orange slices on top of the batter.
Bake for 40 minutes or until a toothpick inserted into the center comes out clean.
Remove from oven and let cool for 15 minutes. Then serve.