Preheat oven to 350 degrees, Line a 12 hole muffin tray with cupcake liners.
In a Lg bowl, add the 3 eggs, 3/4c sugar and 1/4tsp salt.
Using a mixer, beat on med-high for about 5min, untill pale and doubled in size.
Add the grated beets, 1c white flour, ground almonds, cocoa powder and 2tsp baking powder. Stir to combine ingredients.
Add the buttermilk and 1tsp red food coloring, and beat again to make sure that all the ingredients are well mixed.
Spoon batter into the cupcake liners, taking care not to fill more than two thirds of the way up or it will overflow when cooking.
Bake for 30min. While cupcakes are cooking, make the icing.
Prepare a double boiler.
Place all 6 ingredients, Confectioner's sugar, water , vanilla, cream of tartar, egg white and a small pinch of salt in the bowl of the double boiler, and stir to dissolve the sugar with a clean metal spoon for exactly 4min , the mixture should be warm.
Remove the bowl from the heat, and beat with a mixer on high speed, untill cool and the mixture has turned into a meringue, no more than 5min.
The icing mixture is ready to use when it has formed stiff peaks.
Pipe or spread 1 heaping tablespoon of the icing over the cooled cupcakes, and take care to ice the cakes very quickly, as the icing will start to set and is best when just made.