Begin by lining a 9x13 inch baking pan with parchment paper, creating an overhang on the sides.

In a heavy-bottomed saucepan, melt ½ cup of butter over medium heat. Stir in 1 cup of granulated sugar and ¼ cup of light corn syrup; bring to a rolling boil and stir constantly for 1 minute.

Remove from heat, then blend in 1 cup of sweetened condensed milk and 1 teaspoon of vanilla extract until silky smooth.

Pour the warm caramel mixture over 6 cups of Rice Krispies in a large mixing bowl and gently fold until every piece is covered.

Transfer the mixture into the prepared baking pan and press down firmly and evenly, ensuring a smooth top.

In a microwave-safe bowl, combine 1 ½ cups of semi-sweet chocolate chips with 2 teaspoons of vegetable oil. Heat in the microwave at 30-second intervals until completely melted.

Spread the melted chocolate evenly over the pressed Rice Krispies mixture and allow it to cool at room temperature before chilling in the refrigerator for at least 2 hours.

Once chilled, lift the bars out using the parchment paper and slice into squares or bars with a warm knife.