For the cake batter: Preheat the oven to 350 degrees F; line a cupcake pan with 12 cupcake liners.
Put the butter in the bowl of a stand mixer with a paddle attachment and beat slowly until it is smooth and creamy. Add the brown sugar and salt, and cream at moderate speed until the mixture is light and fluffy, 8 to 10 minutes.
Add the eggs one at a time, beating after each addition before adding the next. Mix until light and fluffy, scraping down the sides of the bowl to insure even mixing, about 5 minutes.
Sift together the cake flour, baking powder, baking soda and cinnamon in a medium bowl and set aside. Mix together the milk, sweet potatoes, orange juice and vanilla in a separate bowl. Add one-quarter of the flour mixture to the butter and egg mixture and beat just until blended in. Add one-third of the milk mixture and beat just until blended in. Repeat with the remaining ingredients, alternating the flour with the milk, until all the ingredients are used. Scrape down the sides of the bowl occasionally for even mixing.
Toss the blueberries together with the raw sugar in a small bowl.
Scoop up the batter into the cupcake liners and lay 2 to 3 sugared blueberries on each cupcake. Bake until an inserted toothpick comes out clean, about 22 minutes. Let cool completely before frosting.
For the blueberry filling: Put the blueberries, cornstarch, granulated sugar, raw sugar, cinnamon, orange zest and 2 tablespoons water into a saucepan and set over medium heat. Bring to a boil and simmer until reduced to a jam-like consistency, about 10 minutes.
For the chantilly cream: Using an electric mixer, whip the cream on high in a cold bowl; add the confectioners' sugar and vanilla bean seeds and whip until fluffy.
Use a corer to remove the center of each cupcake and insert some blueberry filling. Cover each cupcake with the chantilly cream.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.