In a large mixing bowl, add all ingredients except for the soy milk and fruit, and mix
Add approximately 1/4 - 3/4 cups of soy milk (or your choice of any other liquid) until the batter is smooth, easy to stir, and slightly liquidy
Line a 9x13 baking pan with wax paper (you can choose any other method of lining/greasing the pan but I have found wax paper makes for the easiest removal of the cake and retains the shape and moisture in the cake best)
Pour in the batter and put in the oven for 30 - 40 minutes or until an inserted toothpick comes out dry.
For the Cake
Mix all the ingredients together.
Cake Assembly
Remove the cake from pan once cool.
Cut cake in half horizontally (this is tricky and may take an extra long knife).
Spread the bottom half with a thin layer of frosting and some berries (or other fruit).
Replace the top half, cover with frosting and finish off with the rest of your fruit.
Notes
When using fruit, be careful about cutting the fruit up and exposing it to the cake. For example, if you cut strawberries and put the strawberries face down on the cake, they will suck the moisture out of the cake and leave the cake slightly dryer.