Combine 1/2 cup plus 2 tablespoons of butter, 1/2 cup plus 1 tablespoon of sugar, and the lemon juice in a medium saucepan. Bring mixture to boil over medium heat.
Blend egg yolks with remaining sugar in a medium bowl, using a whisk. Temper eggs by slowly adding 1/3 of the boiling mixture to the eggs, stirring constantly. Return egg mixture to saucepan, over low heat, and stir the mixture until it boils. Whisk in the lemon zest and remaining butter and remove from the heat.
This recipe was provided by professional chefs and has been scaled down from a bulk recipe provided by a restaurant. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.