1 1/4 cups all-purpose flour
2 1/2 teaspoons baking powder
1/2 teaspoon baking soda
6 tablespoons unsweetened cocoa powder
1 teaspoon salt
1 (15 ounce) can crushed pineapple
Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9 inch square pan.
Sift together the flour, baking powder, baking soda and cocoa. Set aside.
In a large bowl, cream together the sugar, margarine, vinegar, eggs and salt. Beat until very light and fluffy. Beat in the crushed pineapple. Pour batter into prepared pan.
Bake in the preheated oven for 50 to 60 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow to cool completely. Allow to cool completely before cutting into bars.