2 cups brown sugar, packed
2 cups all-purpose flour
1/8 tsp salt
1 large egg
4 ounces butter, cold, cut in pieces
1 cup buttermilk or sour milk
1 tsp baking soda
1 tsp baking powder
1 tsp vanilla
1. Preheat oven to 350 degrees F. Grease and flour an 8-inch square baking pan.
2. Combine flour, brown sugar, and salt in a mixing bowl; cut in butter until the mixture coarse crumbs form. Take out 1 cup of crumbs and put aside.
3. Combine egg, buttermilk, baking powder, baking soda and vanilla, whisk until smooth; stir into the remaining crumbs in bowl. Spread in the prepared baking pan.
4. Sprinkle reserved crumbs evenly over the batter. Bake for 30 minutes.