This is a low sugar version of this Wacky Cake.
1 Preheat oven to 350 degrees F (175 degrees C). Grease one 9 x 13 inch pan, or three 8 inch round pans.
2 Stir together flour, soda, cocoa, sugar, sugar substitute, and salt. Stir in vanilla, water, vinegar, and oil. Pour batter into prepared pan(s).
3 Bake cake in a rectangular pan or three round pans for 35 minutes, or until done. Cool.