1 cup unsalted butter, softened
1 cup white sugar
1/2 cup brown sugar
1/2 cup water
1/2 cup buckwheat flour
1/2 cup water
1/2 cup lemon juice
1/2 teaspoon salt
1/4 cup coldwater
Preheat oven to 350 degrees F (175 degrees C).
In a medium bowl, cream together the butter and sugar until light. Stir in the brown sugar and water. Add the flour, then the salt and lemon juice. Stir together well.
Pour into an 8x8 inch casserole dish and spread evenly. Tint the top with lemon juice, and top with coldwater.
Bake at 350 degrees F (175 degrees C) for 1 hour.