For the cupcakes: Preheat the oven to 350 degrees F. Line a muffin pan with 12 regular-size cupcake liners.
In the bowl of an electric stand mixer with the paddle attachment (or a standard hand held mixer and large mixing bowl), mix the sugar, oil, salt and peaches on medium speed for 30 seconds. Add the eggs and continue mixing on medium speed for 30 seconds. Scrape down the sides and bottom of the bowl with a rubber spatula and mix again on medium speed for 10 seconds. Next, in a blender or food processor, combine the corn and whipping cream and blend for 20 seconds until smooth. Add this creamed corn mixture to the wet ingredients and mix on medium speed until incorporated.
In a medium bowl, sift the flour and baking powder and stir in the cornmeal. Add to the wet ingredient mixture and mix on low speed until incorporated. Now, add the baking soda, followed by the vinegar for an immediate bubbling action. Add 1/4 cup cold water and mix on low speed for 5 seconds. Scrape the sides and bottom of the bowl one last time to be sure all the ingredients are fully incorporated.
Fill the cupcake liners two-thirds full with batter and bake for 18 to 20 minutes. Rotate the pan 180 degrees after 9 minutes of baking. Oven heat and times may vary so bake until the tops are no longer wet and spring back upon touching. Cool the cupcakes completely.
Keep the oven on, but increase the temperature to 400 degrees F.
For the shortcakes: In the bowl of an electric stand mixer with the paddle attachment (or a standard hand held mixer and medium mixing bowl), add the flour, sugar, baking powder and salt. Next, use your fingers to break the butter into pea-size pieces and add to the dry ingredients. Mix on low speed for 30 seconds until incorporated. Add the milk, cream, tarragon and vanilla and continue mixing on low speed until the flour is fully incorporated.
Line a baking sheet with parchment paper. With a spoon, drop heaping spoonfuls of batter onto the baking sheet 2 inches apart and bake for 12 to 15 minutes. Oven heat and times may vary so bake the shortcakes until they are golden brown. Cool the shortcakes completely. With your fingers, break each shortcake into 3 equal pieces and set aside.
For the compote: In a small bowl, combine the blackberries, peaches and strawberries. Add the sugar and gently fold into mixture. Set aside.
For the frosting: In the bowl of an electric stand mixer with the paddle attachment (or a standard hand held mixer and medium mixing bowl), whip the heavy cream on medium-high speed for 3 minutes. In a small bowl, sift the powdered sugar. Add the sugar to the whipped cream mixture and mix on medium-high speed until stiff peaks form. The frosting should be able to stand on its own.
To assemble: Begin assembling the cupcakes by placing a spoonful of peach-berry compote on top of each cupcake. Place the frosting in a piping bag with a round tip or in a gallon-size plastic baggy and snip 1/2-inch off the corner. Next, pipe frosting onto the compote. Place a piece of the tarragon shortcake on top of the frosting. Finally, top with another small spoonful of peach-berry compote. With a tweezer or small tong, delicately place a tarragon leaf on top.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.