Preheat the oven to 350 degrees F; line a cupcake pan with 12 cupcake liners.
For the caramel sauce: In a small, heavy saucepan, mix together the brown sugar, cream, vanilla and salt. Cook over medium heat, stirring occasionally, until the mixture thickens and browns. Set aside to cool. Reserve 1/4 cup for the cake batter and 1/2 cup for the frosting; set aside the rest for drizzling on top of the cupcakes.
For the cake batter: On an ungreased baking sheet, roast the cashews for 5 minutes; cool and chop into pieces. Reserve 1/4 cup for the batter and set aside the rest for garnishing the cupcakes.
Sift together the flour, granulated sugar, baking powder, baking soda and salt in a large bowl. Add the buttermilk, oil, orange zest, vanilla extract, eggs and the reserved 1/4 cup caramel sauce and 1/4 cup chopped cashews. Mix until smooth and completely combined.
Pour the batter into the cupcake liners and bake until golden brown and risen, 8 to 10 minutes. Let cool completely before frosting.
For the caramel frosting: In a medium mixing bowl using an electric mixer, cream the butter. Add the confectioners' sugar 1/4 cup at a time and mix until completely smooth. Add in the vanilla extract and reserved 1/2 cup caramel sauce and mix until combined.
To assemble: Frost each cupcake with some of the caramel frosting. Drizzle the remaining caramel over the top of each cupcake and sprinkle with the remaining chopped cashews. Sprinkle with orange zest to taste. Serve immediately or store in an airtight container for up to 2 days.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.