Chewy Brownies Supreme

I got this recipe from Hersey's cocoa yrs ago and have always loved these brownies. They always seem to turn out so moist and chewy.
½ c. shortening
1 c. sugar
1 t. vanilla
2 eggs unbeaten
½ c. Hershey’s cocoa
3/4 c. sifted all purpose flour
½ t. salt
½ t. baking powder
3/4 c. chopped walnuts (optional)

Cream together shortening and sugar and add vanilla and eggs. Beat until light and fluffy
Add cocoa and mix thoroughly
Soft together the flour, salt and baking powder. Stir in the sifted dry ingredients. Add ½ c. of the chopped walnuts if desired.. Spread the mixture in greased 3x3 pan and decorate top with
remaining 1/4 c. walnuts. Bake 350 for 25 minutes or until done.