In a medium-size bowl, use an electric handmixer to whip the softened butter until creamy.
Zest the blood orange into the butter, then beat mixture until zest is incorporated. Wrap the zested orange in plastic wrap and set aside for later.
Add the granulated sugar to the bowl and beat mixture until light and fluffy.
Pour the lightly beaten eggs in slowly, then beat until mixture is light and creamy.
Add the vanilla and rose water, then beat to incorporate them in the batter. Now, you can put the handmixer aside (you’re done with it).
Gently fold the flour into the cake batter using a spatula or spoon.
Add the 1 tbsp of milk and stir gently to combine.
Scoop the batter evenly into the 12 cupcake cavities; each cavity should be only half-full.
Bake the fairy cakes at 350F for 10-12 minutes, or until a toothpick inserted into the center comes out clean.
Let the fairy cakes rest in the cupcake tin for 10 minutes, then remove them to a wire rack to finish cooling. It won't take very long!