To make sour milk, add 1 ts white vinegar to 1 c milk. Blend flour, butter and cinnamon until mixture resembles cornmeal. Reserve 1 cup flour mixture for top. Add sugar, nutmeg, salt, egg, sour milk and baking soda. Blend slowly. Pour into greased 23 cm square baking dish. Sprinkle reserved crumb mixture on top. Bake at 180ºC or 30 minutes, or until straw inserted in center comes out clean. A light, spicy snack cake