1. Preheat the oven to 325F.
2. Line a baking sheet with aluminum foil then spray it with non-stick cooking spray.
3. Place the pretzels onto the baking sheet in a single layer until it's completely covered.
4. In a small pot, melt the butter and sugar over medium low heat. Bring it to a boil, then continue boiling for 3 minutes, stirring constantly.
5. Pour the bubbly mixture evenly over the pretzels. The caramel mixture will even out when it bakes, so don't worry if you missed some spots.
6. Bake it at 325F for 8 to 10 minutes until the caramel is fully bubbling on the entire sheet.
7. Remove the baking sheet from the oven then sprinkle the chocolate chips evenly over top. Return the baking sheet to the oven for another 1 to 2 minutes to soften the chocolate chips.
8. Use a spatula to spread the melted chocolate evenly. Then place the baking sheet in the freezer for 30 minutes.
9. Remove the pretzel bars from the baking sheet and peel off the aluminum foil. Break it apart or cut it into squares with a large knife.
This is so simple but so very yummy!