Step 1

Preheat oven to 400°F. Combine sweet potato, maple syrup, water and 1 teaspoon cinnamon in a baking pan. Roast in oven until tender, approximately 35 minutes. Purée in a food processor or blender, adding water as needed.

Step 2

Preheat oven to 350°F. Line cupcake pan with cupcake liners, set aside.

Step 3

Cream ½ cup butter and sugars in a stand mixer until light and fluffy. Add egg and yolks one at a time, mixing until each one is incorporated. Add ½ cup sweet potato purée and mix until fluffy, about 1-2 minutes.

Step 4

In a medium bowl whisk together flour, baking powder, baking soda, salt, 1 teaspoon cinnamon and nutmeg.

Step 5

Set stand mixer to low and add the dry mixture in thirds, alternating with milk between each addition.

Step 6

Fill each muffin liner ¾ full and place cupcakes in the preheated oven. Immediately reduce the heat to 325°F and continue to bake for 18-20 minutes, or until toothpick comes out clean when inserted.

Step 7

Allow cupcakes to cool slightly and remove from pan to continue cooling on a wire rack.

Step 8

Add 1½ cups butter and cream cheese to the bowl of a stand mixer fitted with a paddle. Mix until well combined.

Step 9

Scrape down the sides of the bowl, add powdered sugar, vanilla and 1 tablespoon cinnamon. Mix until smooth.

Step 10

Place into a piping bag fit with an extra large drop flower tip and pipe onto completely cooled cupcakes. Garnish with finely zested orange zest if desired.