Mix until all of the powders have completely dissolved into the liquid mixture.
Place the dry ice in the plastic bag and cover it with a towel. (Make sure not to handle the dry ice with your bare hands as it can burn you.) Taking a rolling pin or other heavy object, crush the dry ice into rice-grain-sized pieces.
Take 500 grams, or about 2 1/2 cups of your mixture from Step 2 and add it to the bowl in your stand mixer. Churn on low and then slowly add the crushed dry ice from Step 3. It should take about 5 minutes to achieve the soft-serve consistency.
In order to get the classic swirl pattern on your soft serve, put the ice cream mixture in a piping bag and place in the freezer for about 10 minutes before piping.
Once it has slightly hardened, take it out and pipe into a cone. (I used a wine glass as a stand to hold the cone.)
Finally, if you’re feeling festive, you can add sprinkles, or chocolate sauce, or your favorite toppings. Enjoy!
Notes
You'll want to crush the dry ice a finely as possible, about pea-sized or smaller. This will ensure that the dry ice sublimates completely and freezes the ice cream quickly.