Best Brownies!

I'm a sucker for a good brownie, and these - by far - are the best I've ever had! Thanks Cindy for sharing your recipe!

4 eggs
1 tsp. vanilla
2 cups sugar
1 cup butter
2/3 cup cocoa
1 cup flour
1/2 tsp. baking powder
1/2 tsp. salt
1 cup nuts (optional)

Mix well. Pour into a lightly sprayed 9x13 pan and bake at 350 for 35 minutes