Preheat oven to 350 degrees. Line a 4x8-inch loaf pan with parchment paper.
Heat caramel and 2 1/2 ounces evaporated milk in a double boiler over medium heat. Whisk until smooth.
In a medium-sized bowl, whisk together flour, baking powder, salt and sugar. In a separate bowl, whisk together oil and egg. Add oil and egg mixture to flour mixture.
Place about 3/4 of brownie mixture in lined pan Bake at 350 for about 10 minutes until mixture just starts to set up. Add caramel. Dot with remaining brownie mix. Swirl together with tip of knife. Bake an additional 20 to 25 minutes until inserted toothpick comes out clean.
Cool in pan on wire rack for at least 30 minutes before removing from pan to prevent crumbling. Cut when completely cooled.