In the bowl of a stand mixer, using the whisk attachment, whip the heavy whipping cream until stiff peaks form.
Add the sweetened condensed milk and butter extract, and continue whipping until the ice cream is light and fluffy, and holds stiff peaks.
Line a loaf pan with parchment paper and spoon about half of the ice cream mixture into it. Drizzle with half of the maple syrup and half of the chocolate chips, using a butter knife to gently swirl it all together.
Add the remaining ice cream mixture, maple syrup, and chocolate chips, and again swirl it all together with a butter knife.
Place the ice cream in the freezer and allow to freeze overnight or for 6-8 hours.