In a bowl combine flour and sugar. Cut in butter into the flour and sugar until mixture resembles crumbs. Remove 1/2 cup of the crumb mixture and set aside
To larger part of crumb mixture add egg and molasses.
Blend in 3/4 cup boiling water.
Dissolve soda in remaining 1/4 cup water and add last.
Pour into pie shell. Sprinkle with 1/4 cup reserved crumbs.
Bake at 425 degrees for 15 minutes. Add remaining crumbs and bake 40-45 minutes.
Garnish with whipped cream