This citrus dessert takes the tart flavor of lemons and turns it into a sweet cake. You can serve the Lemon Bar Cake warm, if desired, or let is cool completely. The cake will be similar to a chocolate lava or molten cake. Lining the slow cooker with aluminum foil before adding your ingredients will make cleanup a breeze. Fresh lemon zest adds lots of flavor to recipes. If you are re not sure where to begin, our quick and easy 2-step process will help you create the perfect touch of citrus. One of the most important steps is to make sure that you are only removing the yellow skin and not the white pith, which is very bitter. Cook the cake as directed, and then turn off the slow cooker. Let it stand 15 minutes before serving. When serving, sprinkle individual portions with powdered sugar. Candied Lemon Slices would also make the perfect garnish for the top of your cake. They are simple to make, using only four ingredients, and you can make them while your cake is cooking in the slow cooker.