Preheat the oven to 350 degrees then line a 12-hole muffin tray with cupcake liners.
In a large mixing bowl, add the eggs, sugar and salt, then using a handheld or standing mixer, beat on medium-high for about 5 minutes (until pale and mix has doubled in size).
Add the grated beets, flour, ground almonds, cocoa powder and baking powder; Stir to combine.
Add the buttermilk and food coloring then beat again to make sure that all the ingredients are well-incorporated.
Spoon batter into the cupcake liners (be sure not to fill more than two-thirds of the way up as it will overflow when cooking).
Bake for 30 minutes; While the cupcakes are cooking, make the icing:
Prepare a double boiler; Place all the icing ingredients in the bowl of the double boiler, and stir to dissolve the sugar with a clean metal spoon for exactly 4 minutes; the mixture should be warm.
Remove the bowl from the heat, and beat with a hand or standing mixer on high speed, until cool and the mixture has turned into a meringue, no more than 5 minutes (The mixture is ready to use when it has formed stiff peaks).
Pipe or spread 1 heaping tablespoon of the icing over the cooled cupcakes. ( take care to ice the cakes very quickly, as the icing will start to set and is best when just made).