Preheat the oven to 350 degrees F. Grease an 8-inch square baking dish or a 9-inch round cake pan. (If the pan is dark-coated metal, reduce the oven temperature to 325 degrees F.)
In a medium bowl, mix together the oil and sugar until well blended. Beat or whisk in the eggs and vanilla.
In a separate bowl, combine the flour, cocoa, baking powder, and salt. Add the dry mixture to the wet mixture, and stir until just combined. Fold in 1 cup of the chopped candy. Spread the batter evenly into the prepared pan, and then evenly distribute the remaining 1/2 cup candy over the top.
Bake for about 18-20 minutes, or until the brownies begin to pull away from edges of pan but still appear the slightest bit undercooked in the middle. All ovens vary, so check a few minutes early and know that it might take a few minutes longer.
Allow the brownies to cool, and then cut and enjoy. For easier cutting, chill the freshly cooked brownies in the refrigerator. Once cool, cover the brownies with foil or plastic wrap. You may store at room temperature, but to prolong freshness, you may wish to tightly wrap the brownies and store in the refrigerator.