Preheat oven to 350 degrees. Line a 9x13 baking pan with parchment paper.

• Prepare brownie mix according to the directions on the box spoon into parchment lined pan and bake for 20 minutes. Let cool.  Reduce oven temperature to 325 degrees.
• Pour peanut butter chips into a glass bowl,  place in microwave on high for 30 seconds, remove stir and return to microwave at 30 second intervals until chips are melted and smooth. Allow chips to cool for a few minutes.
• In a large mixing bowl, beat cream cheese until fluffy. Gradually add sweetened condensed milk. Slowly add melted peanut butter chips. Mix on high until smooth. Add eggs one at a time, scraping the bowl after each. Add vanilla, and continue to beat for another 3 minutes or until light and fluffy.
• Pour cheesecake filling over brownie crust, tap pan on counter to remove any air bubbles and to insure filling is evenly distributed over crust.
• Place the baking pan with the brownie crust in a larger pan and pour hot water into the larger pan until the water comes about halfway up around the smaller pan. Place in a preheated 325-degree oven for 50 minutes. Remove and allow to cool in a water bath. When completely cooled, place in the refrigerator for 30 minutes.
• Place chocolate chips, butter, and vegetable oil in a saucepan and melt over low heat, stirring with a rubber spatula the whole time. Remove them from the stovetop when the chips are melted and the ganache is smooth. Taking hold of parchment paper, lift the cheesecake out of the pan, sit on the countertop, and pull the parchment paper down off the sides of the cheesecake. Pour the ganache over the top and smooth out with a spatula.