Adapted from Gingercake on page 85 of Baking at Home with The Culinary Institute of America. Purchase here or see if your library has the book here on Worldcat

1 1/2 cups all-purpose flour
2 t ground ginger
1 t baking powder
1/2 t baking soda
1 t salt
8 T (1 stick) unsalted butter, room temp
1 cup sugar
1/2 c molasses
1/2 c buttermilk
2 large eggs (I always use room temp eggs for baking....leave out for awhile or place in warm water for 15 minutes before using)

1. Preheat over to 350 degrees. Grease and flour a 9-inch square baking pan. (I place a piece of parchment in the pan and spray with Pam with Flour).
2. Sift together flour, ginger, baking powder & soda and salt in a bowl and set aside.
3. Cream together the butter and sugar in stand mixer with paddle attachment until light in texture, about 3 minutes.
4. Add the molasses and buttermilk and beat until evenly blended, about 1 minute.
5. Increase speed to medium and cream until smooth and light, about 2 more minutes.
6. Add eggs one at a time on medium speed.
7. Add the sifted dry ingredients on low speed until evenly blended and smooth.
8. Pour into cake pan and bake until center springs back when pressed lightly, about 45 minutes.
9. Let cool on wire rack. Slice and serve...dust with powdered sugar.

The Food Librarian blog:
Recipe & Photo on the Food Librarian blog (January 14, 2010):