During the early 70's, I obtained this recipe from my aunt, who lived in Minnesota. I haven't made it for a long while (probably because my kids have grown and gone, and I don't eat as many sweets), but when I saw the swap title, this recipe came to mind.
I've seen other recipes similar with the addition of 1 tsp salt, 1 tsp vanilla, and 1 tsp baking powder. I imagine it depends on whether you prefer a more cake like brownie.
This is a simple and convenient recipe to try. You likely have all the ingredients in your pantry, except maybe the chocolate syrup.
I hope you enjoy!

BESTEST BROWNIES

1 stick butter (1/2 cup), softened
1 cup sugar
4 eggs, beaten
1 can (1 cup) Hershey's chocolate syrup
1 cup flour
1 cup chopped nuts

Combine all together and spread into 9x13-inch greased baking pan.

Bake at 350 degrees for 30 minutes.

Optional: when cooled, top with:

SUPERB CHOCOLATE FROSTING

1 1/3 cup sugar
6 tablespoons butter
6 tablespoons milk
1/2 cup chocolate chips

Combine sugar, butter, and milk in saucepan. Bring to boil for 1 minute. Remove from heat and stir in the chocolate chips. Beat until melted.