Add butter to a saucepan and begin to heat on a low heat.
As the butter begin to melt, add brown sugar and 1 cup heavy cream. Stir together and bring it to a boil on a low to medium heat.
Boil for 5 minutes on a medium heat, scraping down the sides every 2 mins. The sauce turns slightly thicker but still looks way runny but it turns thicker after cooling.
Pour vanilla extract. Turn off the heat and cool completely. After cooling down it should be thick and pourable.
Store butterscotch sauce in a cool dry jar and refrigerate. This keeps good for about 3 to 4 weeks.
Chill a large bowl and the whisk or attachments of the stand/ hand mixer for at least 24 hours in the freezer.
Pour the chilled cream to the bowl. Begin to whip on a low speed and then on a medium speed until stiff peaks form.
Pour condensed milk and butter scotch sauce (saving ¼ cup for later). Gently fold the whipped cream, taking care not to deflate it.
Taste test the ice cream. Add more butterscotch sauce for more sweetness.
Transfer to a metal loaf pan. Drizzle some butter scotch sauce & sprinkle praline. Place a cling wrap & press it down over to the mixture to avoid ice crystals.
Freeze overnight or more until the butterscotch ice cream is set.
Scoop the ice cream to serving bowls, Drizzle butterscotch sauce and praline before serving.