Makes 8 sandwiches
For the cookies
½ cup unsalted butter, melted
½ cup sugar
1 egg
1 teaspoon vanilla extract
½ cup all-purpose flour
¼ cup cocoa powder
¼ teaspoon salt
¼ teaspoon baking powder
For the ice cream
1 (300ml) can sweetened condensed milk
1 teaspoon vanilla (or 2 teaspoons vanilla bean paste)
¼ teaspoon salt
2 cups whipping cream
Heat your oven to 350ºF. Grease two 9-inch square baking pans non-stick cooking spray and line with a sling of parchment paper so that it covers the bottom and comes up two of the sides.
In a medium mixing bowl, beat together the butter, sugar, egg, and vanilla until well combined and a little lighter in colour, about 1 to 2 minutes. In a separate bowl, sift together the flour, cocoa powder, salt, and baking powder. Add the dry ingredients to the butter mixture and stir just until combined and the batter is smooth.
Divide the batter equally between the two pans and spread into a thin layer so that it covers the entire base of each pan. Bake in your preheated oven for 8 to 10 minutes or until the edges start to pull away from the sides and the centre of the brownie-like cookies spring back when touched and look slightly dull.
Remove the cookies from the oven and allow them to cool to room temperature before turning them out. Line one of the 9-inch square baking pans with plastic wrap so that it hangs over the edges and place one of the cookies in the bottom. Transfer to the freezer to chill while you make the ice cream.
For the no-churn ice cream, whisk together the sweetened condensed milk, vanilla, and salt in a large bowl. In a separate bowl or the bowl of your stand mixer fitted with the whisk attachment, whip the cream until stiff peaks form, about 2 minutes. Using a rubber spatula, gently fold a third of the whipped cream into the condensed milk mixture. Fold in the rest of the whipped cream in two more additions and set aside.
Retrieve the baking pan from the freezer and pour the ice cream base over the cookie, spreading it into an even layer, and top with the remaining cookie. Gently fold the plastic wrap over top to cover and place in the freezer for at least 6 hours or preferably overnight.
When ready to serve, turn the ice cream sandwich out of the pan and, using a sharp
knife, cut into eight equal portions. Serve immediately or wrap individually and
store in the freezer for up to two weeks.