milk to the saucepan and return mixture to a simmer over medium heat.
once mixture begins to simmer, slowly pour about half of it into the egg mixture, whisking vigorously the entire time. pour this egg mixture back into the saucepan with the remaining milk. bring mixture to a boil and then continue cooking for 1 more minute, stirring constantly the entire time. remove mixture from the heat, and continue stirring for another 2-3 minutes. add the butter and vanilla extract; stir until fully combined and cream is smooth. set cream aside to cool.
heat 1" of water in a medium saucepan until it begins to simmer. place a small, heat-proof bowl 