2 cups flour
1 teaspoon baking soda
1 teaspoon baking powder
1 teaspoon coarse salt
1 teaspoon cinnamon
1 teaspoon ground ginger
1/4 teaspoon freshly grated nutmeg
1/4 teaspoon allspice
1 cup brown sugar, packed
1 cup sugar
1 cup (2 sticks) butter, melted and cooled
1 can (15 ounces) pumpkin puree
1/2 cup sugar
4 tablespoons water
1/2 cup heavy cream
2 teaspoons vanilla extract
1 cup (2 sticks) butter
1/2 teaspoon sea salt
2 to 4 cups powdered sugar
Preheat oven to 350 degrees. Line cupcake pans with paper liners and set aside.
In the bowl of a stand mixer, combine the brown sugar, sugar, butter and eggs. Beat on medium speed until well combined. Add the flour, baking soda, baking powder, salt, cinnamon, ginger, nutmeg, and allspice. Mix on low until smooth. Fold in the pumpkin puree.
Divide the batter among the paper liners, filling only about halfway. Bake for 20 to 25 minutes or until a cake tester inserted in the center comes out clean. Let cool completely.
To make the caramel sauce, combine the 1/2 cup of sugar and water in a sauce pan. Bring to a boil over medium-high heat. Cook without stirring until mixture turns a deep amber color. Remove from heat and slowly add in the cream and vanilla. Stir until smooth. Let the caramel cool for about 20 minutes.
To make the buttercream frosting, in a stand mixer with a whisk attachment, beat the butter and salt together until fluffy. Reduce the speed to low and add 2 cups of the powdered sugar. Continue to add powdered sugar until desired consistency is reached.
Slowly add half of the caramel sauce with the mixer on low speed. Increase speed to medium-high and beat until light and fluffy, about 2 minutes.
Transfer the frosting to an icing bag with a No. 1 star tip and frost the cupcakes. Drizzle the remaining caramel sauce over top of the frosting.