Preheat the oven to 350°F (175°C) and prepare a 9x13-inch baking pan.

Soak the eggs in warm water for about 10 minutes to ensure they're at room temperature.

Cream together 1 cup of unsalted butter and 2 cups of granulated sugar until light and fluffy.

Beat in the soaked eggs one at a time, along with 2 teaspoons of vanilla extract.

In a separate bowl, sift together 2 cups of flour, 1 tablespoon of baking powder, and ½ teaspoon of salt, then add 1 package of pudding mix.

Gradually mix the dry ingredients with the wet ingredients, alternating with 1 cup of cream soda.

Pour the batter into the prepared pan and bake for 40-45 minutes, until a toothpick comes out clean.

Let the cake cool in the pan for 30 minutes before transferring to a wire rack to cool completely.

For the mousse, whisk together 1 package of pudding mix and 1 cup of heavy cream until thick and fluffy.

For the frosting, beat together 8 ounces of cream cheese and ½ cup of unsalted butter until smooth, then mix in 2 cups of powdered sugar and 2 tablespoons of cream soda.

Cut circles from the cooled cake using a cookie cutter to create layers for the jars.

Layer the jars with cake, mousse, and frosting, repeating until filled, and finish with a swirl of frosting on top.