Preheat the oven to the instructed temperature on the back of the brownie mix box. Spray a muffin pan really well with vegetable cooking spray and set aside.
Follow the instructions on the brownie box to create the batter plus the vanilla extract. Then fold the peanut butter mini cups into the batter. Make sure it is well combined.
Evenly fill each muffin cup about ¾ of the way full with the batter.
Bake in the oven for the required time listed on the box, about 25-30 minutes, or until you see cracks on the top of the brownies. You can also check with a toothpick - if it comes out clean the brownies are ready.
After the brownies have finished baking and are still warm, use the back of a spoon to make an indentation for the peanut butter.
In a small microwaveable bowl, melt and mix the peanut butter with the caramel syrup heating in 30 second increments.
Remove the brownies from the muffin pan and transfer them to a cooling rack.
While the brownies are still warm, top each one with the warm peanut butter and caramel sauce. Cool completely.
Once the top is cooled, garnish with a sprinkle of sea salt and chocolate shavings made from the milk chocolate bar.
Best served immediately and warmed. Especially delicious with a cold glass of milk.