For the batter: Preheat the oven to 350 degrees F. Line two 12-cup muffin pans with cupcake liners.
In a medium mixing bowl, combine and sift the flour, rosemary, baking powder and salt, and set aside. In another mixing bowl, combine the sugar and eggs. Using an electric hand mixer, beat on medium-high speed until blended. Add the oil and vanilla and beat together for 1 minute. Add the flour mixture a little at a time, alternating with the buttermilk and lemon mixture. Start and end with the flour mixture. Divide the batter evenly among the lined cups, filling each three-quarters full. Bake until a toothpick comes out clean, 18 to 20 minutes. Transfer to a wire rack and cool completely.
For the filling: Whip the mascarpone until creamy. Add in the lemon juice and lemon zest. Mix in the smoked salmon. Place into a piping bag and put in the refrigerator until ready to use.
For the frosting: Whip together the cream cheese, cream and broth until light and fluffy. Add in a handful of the chopped chives. Place into a piping bag fitted with a large round tip.
Once the cupcakes have cooled, pull out the centers with a cupcake corer. Fill the cupcakes with the smoked salmon filling. Pipe the frosting onto the cupcake and garnish with lemon zest, rosemary pieces and some rolled up smoked salmon.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.