Preheat oven to 350 degrees F (180 degrees C). Spray a 9-inch cake pan with non-stick cooking spray.
In a large bowl, combine the All-Purpose Flour (1 1/2 cup), Granulated Sugar (1 cup), Baking Powder (2 teaspoon), and Kosher Salt (3/4 teaspoon).
In another large bowl, combine Large Egg (3), Ricotta Cheese (1 1/2 cup), Vanilla Extract (1/2 teaspoon), and Unsalted Butter (1/2 cup). Then, slowly combine the flour mixture with the ricotta mixture.
Once combined, pour the batter into cake pan. Place Blood Orange (3) on top and bake for about 45 to 50 minutes or until golden brown.
Remove the cake from oven to cool before slicing and dusting with Powdered Confectioners Sugar (to taste).