In a large bowl, whip heavy cream until stiff peaks are achieved, up to 3 minutes. Set aside.
In a separate bowl, add sweetened condensed milk and vanilla extract. Stir to combine. Set aside.
In a saucepan over medium heat, add butter and brown sugar. Once melted, add chopped pecans and cinnamon, stirring to coat. Cook for 2-3 minutes, or until pecans begin to look sticky and mixture thickens slightly. Remove from heat and pour pecans into sweetened condensed milk mixture. Stir to combine.
Gently fold whipped cream into sweetened condensed milk mixture until fully incorporated. The mixture should look fluffy.
Pour mixture into a 9x5 loaf pan (or any container that will hold 6 cups). Cover and freeze immediately for 4-5 hours or until firm. Enjoy!
Depending on the temperature of your freezer, ice cream may need to be frozen overnight to freeze solid.
Pecans can be substituted with any chopped nuts, like walnuts or hazelnuts.