For the Cupcakes:

1. Preheat oven to 350°F. Line two 12-cup muffin pans with paper liners and set aside.
2. Sift together the flour, sugar, cocoa powder, baking soda, baking powder, and salt in a large bowl.
3. In a separate medium bowl, whisk together the eggs, water, buttermilk, oil, and vanilla extract.
4. With a spatula, mix the wet ingredients into the dry ingredients. Mix until just incorporated, scraping down the sides and bottom as necessary. You will still see some small lumps of dry ingredients. Fold in the chocolate chips.
5. Divide batter evenly among muffin cups, filling each about 2/3 full. Bake for about 20 minutes, or until the tops are fully set and spring back when touched.
6. Remove from the oven, and let the cupcakes cool in the pan for 5 minutes before removing and placing them on a wire rack to cool completely.

For the Vanilla Frosting:

1. In the bowl of a stand mixer fitted with the paddle attachment, mix the softened butter on medium speed until it is smooth, with no lumps.
2. Sift the confectioners’ sugar into a separate bowl. Add one cup at a time to the butter, beating very well after each addition.
3. Add the salt, vanilla, and heavy cream. Mix on medium-high speed until very light and fluffy, approximately 5 minutes.
4. Decorate as you wish immediately on the completely cooled cupcakes, using mini chocolate cupcakes as garnish. Serve and enjoy, or store in the refrigerator until ready to eat.