1 1/2 cups
chopped frozen caramel-filled
POSITION oven racks in top third and centre of oven. Preheat oven to 250F. Line 2 baking sheets with parchment. Stir sugar and cornstarch in a small bowl. Beat egg whites with cream of tartar in the bowl of a stand mixer on medium-high until soft peaks form when beaters are lifted, about 2 min. Gradually beat in sugar mixture, 2 tbsp at a time, until stiff and glossy peaks form when beaters are lifted, about 3 min. Beat in vinegar. Fold in caramel-filled chocolate bar.
DOLLOP meringue by heaping 1 tbsp onto prepared sheets. Using a small wet spoon or finger, make indentations in centres. Sprinkle each with additional chopped candy.
BAKE for 1 hour, turn heat off and let stand in oven for 1 hour more. Transfer to racks to cool completely. Meringues will keep well in an airtight container at room temperature for up to 1 week. Do not refrigerate or freeze. Baking tip: When working with meringue, pipe and bake immediately. Meringue will lose volume if left too long.