To make petit fours all you need is your favorite white or chocolate cake mix. Bake the cake in large pan. Once the cake is cooled, take it out of the pan and slice it right down the middle lengthwise with a damp knife. Some people prefer to make the slice with string or dental floss. Once you have two halves, spread your preserve on one side. Then place the other half of the cake back on top. Next you want to cut your cake into little squares. You can use a ruler to make each one an exact size. Place your cake squares on a pan with a drying rack inside. Now you will need to make your frosting. Mix one cup of water, three cups of sugar and 1/4 tsp. of cream of tartar together in a bowl. Stir very well so that the frosting is not too thick and will spill nicely on the cakes. Once it is made, take your ladle and spoon on the frosting onto the little cakes. Let the petit fours dry for at least 30 minutes. The longer you wait to decorate the better. Wet your fingers with water to take each petit four out of the pan, this way you will not smudge the frosting. You can then decorate them with frosting, flowers, candy or whatever you like. Check out the recipe for sugared grapes and flower petals on the Good Idea page for other decorating recipes.