Preheat oven to 350 degrees. Line cupcake pan with liners (this recipe will make 20-24).
In the bowl of mixer add in all the dry ingredients.
Add the egg, oil, vanilla, milk, mix on medium speed 2 minutes.
On medium speed slowly stream in the boiling water (batter will be thin/watery).
Mix until fully combined scraping sides of bowl and mixing again as needed. Make sure you scrape bottom of bowl, sometimes batter sticks to it, you want to be sure all the ingredients are well mixed together.
Pour into prepared cupcake pan(s).
Bake 13-15 minutes or until toothpick inserted comes out clean.
Let cool completely.
Melt butter, add to bowl of mixer. Stir in cocoa. With mixer on low/med add the powdered sugar alternating with the milk.
Add the vanilla, mix until combined.
Preheat oven to 225 degrees F.
Line baking sheet with parchment.
In bowl of mixer with whisk attachment mix the egg whites until frothy. Add in the sugar 1 tsp at a time while mixing on medium. Add in the cream of tarter and vanilla
Increase speed and mix until egg whites are glossy and hold a stiff peak (but not dry).
Color as desired (optional). If using 2 colors you'll need 2 piping bags, etc.
Fit pastry bag with desired tip and fill piping bag with meringue.
Pipe onto parchment lined baking sheet.
Place in oven, reduce temp to 200 degrees F.
Bake 1 1/2 hours (or until meringues are dry to the touch and release from the parchment easily).
Cool completely. Store in cool, dry place.
Put a generous dollop of frosting on each cupcake and swirl it around.
Add berries and meringues.
Repeat until all cupcakes are done.
Drizzle them with melted chocolate.