Set oven at 350 degrees. You can use foil inside the pan to make the brownies easier to remove*; either way the pan or the foil must be coated with shortening or butter and dusted with flour.
Melt butter over low heat until there is a coating of melted butter on the bottom of the pan, then add chocolate and continue to melt slowly, stirring occasionally. Do not heat too fast or the chocolate will stick to the bottom or burn. Make sure that no water gets into the pan or the chocolate will coagulate. When chocolate and butter are both melted together take off of heat.
Add the sugar and vanilla and mix. Add the beaten eggs. Mix until eggs are completely mixed in. Add the flour, salt, and baking powder and mix. Only mix until the flour is no longer visible. Don’t over-mix or the brownies will be cakey.
and scrape brownie batter into 9 X 12 inch pan(s). Put in center of
oven and cook for about 25 minutes. Cool for about a half hour before trying
to remove from pan.
*Tips from Mom: Use foil on the pans to help get the brownies out without breaking them. Put the pan upside down and fold the foil over it, then flip the pan and put the foil inside and make sure that there is enough to wrap over the short ends.Then grease and flour the foil. When the brownies are baked, you may need help to remove them. Sometimes 4 hands one on each side keep the brownies from cracking. If you don't have 4 hands just wait till they are only warm. You'll have to do a little back and forth flipping between racks to get the foil on top so that you can peel it off. I don't recommend cutting the brownies still on the foil. If they have cooled so much that you can't peel the foil off without having it pull off the brownie parts, just heat the foil up a little with a hairdryer.