1/2 cup butter
2 cups white sugar
1 teaspoon vanilla extract
1 cup all-purpose flour
2 teaspoons baking powder
1 1/2 teaspoons baking soda
1 cup chopped pecans
3 tablespoons confectioners' sugar for dusting
Preheat oven to 350 degrees F (175 degrees C). Grease and flour 2 (9 inch) round pans.
In a large bowl, cream together the butter and sugar until light and fluffy. Mix in the flour, baking powder, baking soda and pecans. Beat in the butter mixture. Combine the sugar and flour mixture; beat into the creamed mixture. Stir in the pecans.
Dust with confectioners' sugar for dusting the cake. Dust with additional confectioners' sugar if desired.
Bake in the preheated oven for 35 to 44 minutes, or until a toothpick inserted into the center of the cake comes out clean. Let cool in pan for 30 minutes, then invert onto a wire rack and cool completely.
To make the topping: Combine 3 tablespoons confectioners' sugar with 2 tablespoons margarine and 1/2 cup chopped pecans. Mix together and spread over the cooled cake.