My Mom's Chocolate Cake

1 1/4 stick margarine
1 tsp vanilla
3 eggs
1 2/3 c sugar
2 c flour
2/3 c cocoa
1 tsp baking powder
1 tsp baking soda
1 1/2 c milk
1 tsp salt

Bake at 350 in a 9 x 13 pan for 35 minutes.