In medium saucepan melt 3 tbsp butter over low heat.
While butter is melting, spray baking tray with baking spray. Additionally, rub butter along inside of medium mixing bowl until covered & pour in Rice Krispies.
When butter is full melted, pour marshmallows into saucepan & stir continually until smooth.
Pour marshmallow & butter mixture over Rice Kripsies & stir until well coated.
Place mixture in baking tray and press down gently until about ¾ in. thick.
Cut out heart shapes with cookie cutter.
Combine all ingredients to make frosting & top Rice Krispie treats with frosting & Pop Rocks.
Enjoy!