These bars can be served plain or with powdered sugar. To create a darling heart shape in the middle of each bar, simply cut out a one-inch heart from a piece of parchment paper or paper towel, lay it in the middle of a bar, and coat with powdered sugar using a sieve. Quickly remove the heart stencil and repeat for each bar.
You can also make the bars even more decadent by spreading on a layer of cream cheese frosting.
If you want to make a tray of thinner bars, spread the ingredients in a wider pan or halve the recipe using the same size pan but bake for less time.