Preheat the oven to 180C/350F. Grease a 7-inch springform cake pan and set aside.
In a large mixing bowl, combine your dry ingredients and mix well. Add your wet ingredients and mix until a smooth batter remains.
Transfer your cake batter into the greased cake pan and bake for 25-30 minutes, or until a skewer comes out clean.
Remove the cake from the oven and let cool in the pan completely. Once cooled, frost.
For the frosting
Beat together the butter and powdered sugar until combined, Add in the vanilla extract and add the water, one tablespoon at a time, until smooth.
Notes
To make a triple layer cake, triple the ingredients and frosting. TO STORE: Leftover cake can be stored at room temperature, covered, for up to 5 days. If you'd like to keep it longer, store it in the refrigerator for up to 2 weeks. TO FREEZE: Place slices of the cake in a shallow container and store in the freezer for up to 6 months.