PREPARATION. Preheat oven to 210 F (100 C). Line baking sheet with parchment paper. Set aside.
MAKE THE MERINGUE. In a grease-free bowl of a stand mixer fitted with a grease-free whisk attachment, whip the egg whites on low speed until bubbles start to form. Increase speed to high and continue whisking until stiff peaks form. Add the sugar one big spoonful at a tie while mixer is running at medium speed. Once all the sugar is added, add the vanilla extract and few drops of your food coloring (until the desired color is achieved) then continue mixing for another 5-7 minutes. You should be able to rub the mixture between your fingers and not feel any grit. If there is, mix again for another 1 minute until the mixture is smooth and glossy.
PIPE THE MERINGUE. Transfer the meringue mixture into a large piping bag. Snip off the tip of the piping bag about an inch in diameter and pipe kisses on the lined baking sheet, about 1 inch apart. Gently put sprinkles over the kisses.
BAKE. Bake for 40-50 minutes. You'll know when they're ready if the kisses can be easily lifted off the parchment paper with bases intact. If not, return them back in the oven for another minute. When the meringue kisses are done, turn of the oven but leave them inside until completely cool.
COOL AND STORE. Remove meringues from paper and store in an airtight container at room temperature.
Notes
(Note 1) This recipe uses this ratio: one part egg whites to two parts sugar. So if your egg whites weigh 70 grams, use 140 grams of sugar; if you got 90 grams of egg white then use 180 grams of sugar.
(Note 2) Liquid food coloring (water-based) is not suitable as the extra liquid can thin out the mixture.
(Note 3) You can use other piping tips to make designs. In the photos above I used a large, plain piping tip and this Wilton open star tip.
(Note 4) Don't have superfine sugar? You'll only need 5 minutes to make your own.