Step 2While you prepare the condensed milk, make the chocolate cookie. Preheat the oven to 150 °C/ 300 °F (fan assisted), or 170 °C/ 340 °F (conventional).
Step 3Place the almond flour, cacao powder, Erythritol, baking powder, and salt into a mixing bowl and combine well. Add the egg and coconut oil and mix with your hands. (Note: to get 1 tsp baking powder you can use 1/2 tsp cream of tartar + 1/4 tsp baking soda).
Step 4Place the dough on a sheet of parchment paper, top with another sheet of parchment paper, and roll out, or simply use your hands to flatten it until about 1/4 inch (1/2 cm) thick, to create a large cookie.
Step 5Transfer to a baking sheet and bake in the oven for 12-15 minutes or until crispy. Let the cookie cool to room temperature. The cookie will be soft at first but will crisp up as it cools down.
Step 6Once cooled and crisped up, break the cookie into small pieces.
Step 7Place a large container in the freezer. (I used an 8-inch/ 20 cm square baking dish lined with parchment paper. Any 9-10 cup container will work).
Step 8In a bowl, whisk the cream until soft peaks form. Be careful not to over whisk it to avoid curdling.
Step 9Gently fold the whipped cream into the cooled condensed milk. At first, add a few tablespoons to lighten the mixture, and then gently mix in the remaining whipped cream without deflating it. Mix in the cookie pieces (reserve some for topping).
Step 10Remove the container from the freezer and spoon in the ice-cream mixture. Top with the reserved cookie pieces. Place in the freezer and freeze for 4-6 hours before serving. The ice cream can be stored in the freezer for up to 3 months.