- Preheat the oven to 350°F (175°C). Grease or line a 9×13-inch baking pan with parchment paper, leaving an overhang for easy removal. 
- In a large bowl, whisk together the melted butter and brown sugar until smooth and combined. 
- Add the eggs and vanilla extract, mixing well. 
- In a separate bowl, sift together the flour, baking powder, and salt. Gradually add to the wet ingredients, stirring until just combined. 
- Fold in the oats, then gently stir in the chocolate chips and caramel bits, saving a small handful of each for topping. 
- Press half of the batter evenly into the prepared pan. Sprinkle the reserved chocolate chips and caramel bits evenly over this layer. 
- Crumble the remaining batter on top to form the second layer. 
- Bake for 30-35 minutes, or until golden brown and caramel is bubbling. 
- Let cool completely in the pan before slicing into bars.