1. Preheat oven to 350°F (176°C). Grease a 9×9 baking pan or line it with parchment paper or aluminum foil, which you can use to remove the brownies from the pan when they are done.
2. Combine the butter, sugar and vanilla extract in a medium sized bowl.
3. Add eggs and mix until well combined.
4. Combine flour, cocoa, baking powder and salt in another medium sized bowl.
5. Slowly add dry ingredients to the egg mixture until well combined.
6. Pour the batter into the pan and spread evenly.
7. Bake for 18-20 minutes, or until a toothpick comes out with a few moist crumbs.

ONCE THE BROWNIE IS COOLED, MAKE THE FUDGE:

8. Combine sweetened condensed milk, butter, chocolate chips and Nutella in a metal or glass bowl. Set the bowl over a pot of simmering water.
9. Stir mixture until everything is melted and smooth, then spread evenly over the brownies.
10. Set brownies in refrigerator to set.
11. Once set, add chocolate chips and shortening for topping to a microwave safe bowl. Microwave on 15 second increments until the chocolate and shortening are melted and smooth.
12. Spread chocolate into an even layer over the fudge.
13. The chocolate should cool quickly and become firm. Cut into bars.

Store brownies in an airtight container in the refrigerator. Brownies are best for 2-3 days, but should be ok for up to 4-5 days.