Ultimate Birthday Cupcakes

Bahan-bahan (14 porsi)

• 1 batch confetti cupcakes (or any cupcakes!)
• 3 large egg whites, room temperature*
• 3/4 cup (150g) granulated sugar
• 1/4 teaspoon cream of tartar
• 1 teaspoon pure vanilla extract
• pinch salt
• 10 ounces (280g) semi-sweet chocolate, coarsely chopped*
• 1 and 1/2 Tablespoons canola or vegetable oil
• optional: sprinkles for topping