Line muffin pan with cupcake liners and preheat oven to 350 degrees F.
In a small mixing bowl, combine cocoa power and water. Set aside
In a medium mixing bowl, combine flour, baking soda, baking powder and salt. Set aside.
In a microwave safe bowl, melt butter. With an electric mixer, beat in sugar at medium-low speed until butter has cooled (about 4 minutes).
Beat in 1 egg at a time (scrap sides of bowl as needed). Next, add vanilla and chocolate mixture, beating until combined.
Mix on low, alternately adding flour mixture and sour cream in two batches mixing between adding each until just combined.
Fill cupcake liners 3/4 full and bake for 15-18 minutes or until toothpick come out clean.
Immediately remove cupcakes from tin and place on a cooling rack that is resting on a cookie sheet (or something to catch drippings).
Using a fork or skewer, poke lots of holes into the top of each cupcake. Pour the sweetened condensed milk over cupcakes (this has to be done when the cupcakes are warm), followed by the caramel topping.
Allow cupcakes to cool completely and then pipe on Baker's Frosting (I used a closed start tip). Sprinkle frosting with Heath.