Poop Emoji Cupcakes

To prepare frosting: Poke holes all over sweet potato. Microwave on High, turning once, until soft, about 10 minutes total. (To roast, preheat oven to 425 degrees F. Poke holes all over sweet potato and place on a foil-lined baking sheet. Bake until tender, about 1 hour.) When cool enough to handle, scoop the flesh into a food processor. Process until smooth.

Add 1/2 cup chocolate chips to the warm sweet potato puree and blend until the chocolate is melted and the mixture is smooth. Repeat with the remaining chocolate chips, adding 1/2 cup at a time and blending until fully incorporated. Add 1/2 teaspoon vanilla; process until blended. Transfer the frosting to a bowl. Cover the surface with plastic wrap and let cool completely.

To prepare cupcakes: Preheat oven to 350 degrees F. (If you roasted the sweet potato, reduce the oven temperature to 350 degrees F.) Line 12 (1/2-cup) muffin cups with paper liners.

Whisk all-purpose flour, whole-wheat flour, cocoa powder, baking soda, salt and baking powder in a medium bowl.

Beat granulated sugar and butter (or coconut oil) in a large mixing bowl with an electric mixer on medium speed until creamy. Add eggs and vanilla; beat until combined. With the mixer on low, alternately mix in the dry ingredients and buttermilk, starting and ending with the dry ingredients and scraping the sides of the bowl as needed, until just combined. Divide the batter among the prepared cups.

Bake the cupcakes until a toothpick inserted into the center comes out clean, about 20 minutes. Let cool in the pan for 5 minutes, then transfer to a rack to cool completely.

Place the frosting in a decorating bag fit with a large round tip. If using, trim several marshmallows into small mouths. Working with one cupcake at a time, pipe a few swirls of frosting onto the top, then press two candy eyes in place. Finish with a marshmallow or sprinkle for a "mouth." Refrigerate until ready to serve.