Preheat and Prep: Preheat oven to 350°F (175°C) and line a muffin tin with 12 cupcake liners.

Make Cupcake Batter: In a large bowl, mix the yellow cake mix with the canned sweet potato puree, cinnamon, and nutmeg until well combined.

Make Graham Cracker Crust: In a small bowl, combine the crushed graham crackers, melted butter, sugar, and salt.

Assemble Cupcakes: Press about 1 tablespoon of the graham cracker crust mixture into the bottom of each cupcake liner.

Add Batter: Scoop the cupcake batter on top of the crusts, filling each liner about ¾ full.

Bake: Bake until the cupcakes are golden and a toothpick inserted in the middle of a cupcake comes out clean, about 22 minutes.

Cool: Let the cupcakes cool completely.

Make Marshmallow Frosting: Meanwhile, make the marshmallow frosting. In a large bowl, beat together the softened butter and marshmallow crème until combined. Add the powdered sugar, vanilla extract, and salt and beat until smooth.

Frost Cupcakes: Transfer the frosting to a piping bag fitted with a large closed star tip (or use a spatula) and pipe the frosting onto the cooled cupcakes.

Garnish: Garnish with chopped toasted pecans and cinnamon sugar.

Serve: Enjoy!