1. Preheat oven to 180°C (350°F). Grease and line a round cake tin.
2. In a bowl, sift together flour, salt, and bicarbonate of soda.
3. In another bowl, whisk sugar, water, oil, vinegar, vanilla, and food coloring until combined.
4. Pour the wet mixture into the dry mixture. Gently stir until smooth, don’t overmix.
5. Pour batter into prepared tin.
6. Bake for 25–30 minutes, or until a toothpick comes out clean.
7. Let cool before removing from tin.
8. For a Simple Eggless Rainbow Cake, repeat the recipe for each layer with a different color. Stack and frost with buttercream (store-bought or homemade).

Tip: Using gel food coloring yields brighter results without adding too much liquid.