Salted Caramel Ice Cream

I found this recipe online and sent it to my sister as an idea for dessert on Mother's Day. She and my dad made it up for us, and it was delicious!{Salted Caramel Ice Cream}
original recipe here
3 1/2 cups 2% reduced-fat milk
3 large egg yolks
1 1/4 cups packed brown sugar
1/4 cup heavy cream
1 tablespoon butter
1/2 teaspoon sea salt
1/2 teaspoon flake salt

Place milk in a medium saucepan over medium-high heat. Heat to 180° or until tiny bubbles form around edge of pan (do not boil). Place egg yolks in a large bowl; stir with a whisk. Gradually add half of hot milk to yolks, stirring constantly. Return yolk mixture to pan.

Combine sugar, cream, and butter in a large saucepan over medium heat; bring to a boil, stirring until sugar melts. Cook 3 minutes without stirring. Remove from heat; stir in sea salt. Gradually add caramel mixture to yolk mixture, stirring constantly. Return pan to low heat; cook until a thermometer registers 160°. Place pan in a large ice-filled bowl until completely cooled, stirring occasionally. Pour mixture into the freezer can of an ice-cream freezer; freeze according to manufacturer's instructions. Drain ice water from freezer bucket; repack with salt and ice. Cover with kitchen towels, and let stand 1 hour or until firm. Scoop about 1/2 cup ice cream into each of 10 dishes; sprinkle evenly with flake salt.