Production method: 1, first prepare a large basin of ice water for use. 2, half a cup of milk, pour corn starch, and then stir until fully dissolved, set aside. 3. Pour the remaining milk into the pot, add cocoa powder and white sugar, and heat it with medium heat. During the heating process, keep stirring with an egg beater until the instant coffee is added after boiling. 4. Pour the mixture of milk and starch into the pot, mix with the mixture just boiled, continue to cook with medium heat, stir while cooking, and immediately turn off the fire after boiling. 5. Add vanilla powder and half of chocolate. Be sure to keep stirring with an egg beater. 6. Put the pot in the prepared basin of ice water to cool down, and keep stirring the mixed liquid when cooling down. 7. Finally, put the prepared ice cream in the refrigerator and freeze it for one night. The next day, according to the instructions of the ice cream machine, pour in the ice cream liquid and make the ice cream.