Bake Cake
Preheat oven to 350ºF.
Combine flour, sugar, salt, baking soda, and cocoa powder.
Combine water, vanilla extract, and vinegar.
Add oil and water mixture to dry ingredients. Stir until smooth.
Pour batter into baking dish.
Bake 35 minutes.
Cool cake completely.
Make Frosting
Combine powdered sugar, cocoa powder, and vanilla extract.
Add water, 1 Tbsp at a time, until thick but pourable.
Pour frosting over cooled cake and spread.
Slice into 9 pieces.
