Prepare the jars: Begin by cleaning and drying your jars thoroughly.
Mix the cake batter: Mix your cake batter according to the instructions on the package or make it from scratch.
Bake the cake: Preheat your oven to the temperature recommended on the cake mix box or cake recipe.
Place the batter in the prepared sheet pans. Bake, rotating the pan halfway through the cooking process, bake for about 25-30 minutes, until a toothpick inserted into the center comes out clean. Once the cakes are done, let them cool completely before frosting.
Cool & frost: Once cooled, using a 2-inch round cookie cutter, cut out circles of the cake you baked. You will need 1 cake round for a 4oz (about 118.29 ml) mason Jar and 2 cake rounds for an 8oz (about 236.59 ml) mason jar.
Spoon the frosting into a piping bag and pipe frosting in the bottom of each jar add one cake round on top of the filling. Lastly, pipe another layer of frosting onto the top of each cake.
If using, a bigger jar such as an 8 oz (about 236.59 ml) mason jar, repeat the process of adding another cake round and piping another layer of frosting onto the top of each cake. You can also add sprinkles of your cake scraps as crumbles on top of your filling.
Serve: Screw the lids onto the jars and serve your cake in a jar for a unique and fun dessert.
