1/2 cup butter
2 cups brown sugar
2 eggs, beaten slightly
1 tablespoon vanilla extract
1 cup all-purpose flour
2 teaspoons double-acting baking powder
1 teaspoon salt
Melt butter in saucepan. Stir brown sugar into butter until dissolved. Cool slightly and beat in egg and vanilla. Sift flour with baking powder and salt. Stir dry ingredients into butter/sugar/egg.
Butter a 9 inch square pan, line with wax paper, then butter and flour the wax paper. Pour batter into pan. Bake at 350 degrees for 30-45 minutes.