Preheat the oven to 350°F. Line 12 muffin cups with cupcake liners.

Place the sugar and butter in the bowl of a stand mixer fitted with a paddle attachment, and cream on high speed until it is light and fluffy, scraping down the bowl as needed, about 3-4 minutes.

Add the eggs, one at a time, and mix until well combined. Meanwhile, in a small bowl, whisk together the gluten free all purpose flour, cocoa powder, baking powder, and salt. In a measuring cup, mix together the milk and vanilla extract.

Beginning and ending with the flour mixture, add ⅓ of the flour mixture. Mix until just combined, and add ½ of the milk mixture, mixing until just combined. Repeat with another ⅓ of the flour mixture and remaining milk mixture. Finally, add the remaining flour mixture, and mix until just combined, again scraping down the bowl as needed.

Divide the mixture evenly among the muffin cups. Place the cupcakes in the oven, and bake for 15-18 minutes, or until the cupcakes spring back when gently pressed in the center (you can also insert a toothpick in the center, and pull the cupcakes from the oven when the toothpick comes out clean). Let the cupcakes cool in the pan for 3-4 minutes. Remove from the pan, and place on a cooling rack to cool completely.

While the cupcakes are cooling, prepare the frosting. Place the cream cheese in the bowl of a stand mixer fitted with the paddle attachment. Beat on high speed until it becomes smooth. Add the butter and the salted caramel sauce, and beat on high until well combined and smooth, scraping down the bowl as needed.

Add the powdered sugar and salt. Turn the mixer on low until all the sugar is incorporated. Scrape down the bowl, and then turn the mixer on medium for 2 minutes. Scrape down the bowl, and turn the mixer on high for 3-5 minutes, or until the frosting is light and fluffy.

Once the cupcakes are cool, place frosting in a piping bag, and cut the tip of the bag off. Pipe a generous amount of frosting on each cupcake. If desired, top with more caramel sauce and a small pinch of salt.