Preheat oven to 350 degrees.
In one large bowl, add pureed carrots, granulated sugar, greek yogurt, oil, beaten eggs, and vanilla extract.
In a separate bowl, sift together flour, baking powder, baking soda, salt, cinnamon, and nutmeg.
Slowly add the dry ingredients to the wet ingredients and mix until well incorporated.
Scoop batter into cupcake lined muffin pan.
Bake for 23-26 minutes or until toothpick inserted into center comes out clean.
Cool cupcakes on cooling rack.
Add butter to the bowl of your mixer and slowly mix in powdered sugar then turn mixer to high to blend until creamy.
Add in your orange juice and zest until smooth.
Frost cupcakes after they have completely cooled then serve.