S'mores Rice Krispie Treats

Bahan-bahan (24 porsi)

• nonstick cooking spray
• two 10-ounce bags (566g; 11 heaping cups) miniature marshmallows, divided
• 1/2 cup (8 Tbsp; 113g) unsalted butter
• 1 teaspoon pure vanilla extract
• pinch salt
• 7 cups (190g) crispy rice cereal
• 1 and 1/2 cups graham crackers, broken into small pieces (6 graham crackers; 90g)
• 3 Hershey’s milk chocolate bars, broken into pieces (1 heaping cup; 129g)
• 1 –2 Hershey’s milk chocolate bar(s), melted