Combine the freshly squeezed lemon juice and apple juice in a large cup and put in the fridge.
Next, add the almond milk, coconut creamer, sugar, cornstarch and salt to a small pot and turn the heat to medium. As soon as the liquid starts to simmer, whisk for a couple of minutes continuously until the cornstarch and sugar have dissolved. Make sure the cornstarch has dissolved. Turn off the heat and pour the liquid into a bowl and place in the fridge to chill for a couple of hours.
Once it is completely chilled, add the liquid, lemon juice mixture and maple syrup to a blender. Pulse just for a minute until well combined. Pour into your ice cream maker and let it run for 25 minutes until a soft serve consistency is reached. Eat now or let firm up in the freezer for 2-3 hours. If it completely freezes, let it sit at room temperature for 15 minutes before serving.