Line a loaf pan with foil and spray the foil with cooking spray; set aside.
Combine the caramel bits and heavy cream in a small microwave-safe bowl. Microwave on high for 1 to 1½ minutes, stirring every 30 seconds, until melted and smooth; set aside.
In a medium saucepan over low heat, combine the milk chocolate chips and the sweetened condensed milk. Stir constantly until the chocolate is fully melted and the mixture is smooth.
Stir in the vanilla extract, a pinch of salt, and the Rice Krispies until evenly distributed.
Keep the heat on very low. Spoon half of the chocolate mixture into the prepared loaf pan and spread into an even layer.
Spread the melted caramel evenly over the chocolate layer in the pan.
Stir the remaining chocolate mixture in the saucepan briefly, then pour it over the caramel and spread gently to cover.
Let the pan sit at room temperature for a few minutes, then transfer to the refrigerator and chill until completely firm before cutting into squares.