Preheat the oven to 350°F and prepare three round 9-inch pans. (You can grease and flour them or I use the baking spray with flour in it)
In a medium mixing bowl, stir together the flour, baking powder and salt with a whisk to ensure no clumps. Set aside.
In your mixer bowl, cream the butter until smooth. Add sugar and vanilla and beat until completely incorporated. Be sure the scrape the sides and bottom of the bowl.
Add half of the dry ingredients, mix on low until incorporated. Scrape the sides of the bowl and then add half of the milk, again mixing on low until incorporated. Repeat, adding the remainder of the dry ingredients and then the milk. Scrape the sides well.
Add the egg whites (you add them unbeaten) and beat batter on high for 2 minutes. It is ok if the final batter isn’t completely smooth.
Divide the batter into the three prepared pans. Tilt them a bit to level out the batter, and then drop them from a few inches above the counter to finish leveling them.
Bake for about 30 minutes. The sides should have pulled away from the edges and the top should be golden brown and barely spring back when pressed with a finger tip.
Run a knife around the edges of the cakes when you remove them from the oven, then let them cool for 5 minutes in the pan. Invert onto a cooling rack and then cool right side up until completely cooled.
Frosting
In a saucepan, combine dragon fruit and granulated sugar. Cook over medium heat stirring occasionally until it comes to a boil. Stir frequently and allow to boil until thick and syrupy, about 5-7 minutes. Remove from heat and cool completely. You can stick the mixture in the refrigerator if you want to speed up the process.
Once the dragon fruit is cooled, cream the butter until smooth and airy. Add 2 cups of powdered sugar, the salt and vanilla. Beat until incorporated.
Add the dragon fruit and beat until well mixed. Add powdered sugar until you reach your desired consistency.
Assembly
Place 1 layer of cooled cake on your serving plate. Pipe a ring of frosting around the top of the cake to form a dam, then fill with half of the blood orange curd.
Place the second layer on the cake and repeat the process with a frosting dam and blood orange curd.
Place the final layer of cake on top. Frost the cake with remaining frosting.
Chill until about ready to serve.
Cut papaya in half and remove seeds. Peel the skin off the flesh and cut the flesh into thin slices. Arrange slices starting with a large circle around the outer edges of the cake and work your way in. Fill the center circle with pomegranate arils. Chill until ready to serve.