Line your baking sheet with parchment paper and set it aside. Preheat the oven to 200°F.
Put the egg whites and cream of tartar in a clean bowl. Beat the eggs using an electric mixer starting at low speed. While mixing, gradually add the sugar and increase the mixer speed to the highest setting.
Keep mixing for about 10 minutes, then check if the mixture forms semi-stiff peaks.
Using a spoon, transfer the mixture to a piping bag with Wilton tip #21.
Pipe out mini meringues onto the lined baking sheet. Each cookie should be about 1½ inches in diameter and 1 inch in height.
Bake the meringues for 2 hours. After the oven timer is done, turn off the heat and leave the meringues inside the oven for another 40 minutes.
Take out the baking sheet from the oven and let the meringues rest for about 10 minutes to let cool completely.
Place the white chocolate chips in a microwave-safe bowl, then place it in the microwave and heat at 30 second intervals until completely melted. Mix it between each interval.
Place the sprinkles in a separate bowl.
Dip the bottom part of the meringue in the melted chocolate, then dip it in the bowl of sprinkles. Repeat the process for the remaining meringue cookies.
Place the mini meringues in the refrigerator, allowing the chocolate and sprinkles to set, for at least 20 minutes. Serve and enjoy!