Gather your ingredients.
Combine together the egg yolks, sugar, and salt in a bowl.
Whisk until well blended.
Slowly add the flour and continue to stir.
Heat the half & half over the stove until simmering. Slowly add some of the half and half into the yolk mixture for tempering while stirring.
Then pour the yolk mixture into the sauce pan while stirring. Careful to not use too much heat or your eggs may "scramble up". 😉 Continue to stir until thickened (about 5 minutes).
Increase the heat and stir until it is bubbling. Remove from the stove and stir in the butter and vanilla until well blended and smooth.
Give it a taste test!
Place into a bowl and cover the top of the cream directly with plastic. Refrigerate for at least two hours, and up to a day before using.