Preheat the oven to 350 degrees F. Line 2 (12-cup) muffin tins with gold foil cupcake liners.
In a large mixing bowl, combine the cake mix, butter, milk, and eggs. Using a hand mixer beat on medium speed for 2 minutes, scraping down the sides of the bowl to be sure the batter is well incorporated. In a small bowl, mix together the 1/2 can of dulce de leche with 1 cup of cake batter and set aside.
Using an ice-cream scoop, fill the muffin tins halfway to the top with the batter. Spoon a level tablespoon of the dulce de leche mixture into each cupcake liner, and with a butter knife swirl it into the batter. Bake until the tops are golden brown, and a toothpick inserted in the center comes out clean, about 10 to 12 minutes. Remove the cupcakes from the oven and cool in the tins for 5 minutes. Transfer the cupcakes to a cooling rack to cool completely.
Frosting: In a cold mixing bowl, beat the cold heavy cream with a hand mixer until just before soft peaks form. Add the dulce de leche and beat until well incorporated and soft peaks form. Frost each cupcake with the caramel frosting, and sprinkle with gold dragees. Arrange the cupcakes on a serving tray and serve.