Chill a bread pan in the freezer.
Whip cream until stiff peaks form (this takes my mixer about 10 minutes).
Pour sweetened condensed milk into separate bowl and add vanilla. Stir until well mixed.
Scoop 1 cup of cream and fold into milk.
Fold lightened milk into cream until well combined.
Pour ice cream into chilled bread pan and smooth. Press wax paper down firmly, then place in freezer.
Allow to freeze for 2 hours. Remove from freezer and stir. If you are adding mix-ins, stir them in now.
Replace wax paper and put ice cream back in freezer.
Allow to freeze until hard.