Cream the butter and brown sugar until light and fluffy. Beat in the eggs. Beat in the syrup, and the vanilla. Combine the flour, baking powder, ginger, salt, and baking soda; and add to the creamed mixture, alternately with the milk, beating well after each addition. Stir in the pecans. Bake at 350 degrees for 20-25 minutes. Cool.
FROSTING: Meanwhile cream the butter, cream cheese, brown sugar and salt until light and fluffy. Beat in the syrup and the vanilla. Gradually beat in the powdered sugar until smooth. Refrigerate for 1 hour. Frost the cooled cupcakes, and top each with a pecan half.