Preheat oven to 350 degrees F.
I use parchment paper sheets on my cookie sheets and reuse them for all my batches that day.
In your mixer bowl (or large bowl with hand-mixer) cream butter and sugar until light and smooth, about 2-3 minutes.
Beat in the egg, vanilla extract and lemon emulsion, until smooth.
In a separate small bowl, combine flour, baking soda and salt. Add to wet ingredient mixing bowl a little at a time.
If desired, you can add some yellow flood coloring just for fun.
Mix until thoroughly blended.
Add white chocolate chips and mix by hand.
Form dough into balls about 1.5" in size and place a few inches apart on parchment lined cookie sheet.
Bake at 350 for 12 minutes. They will be puffy, and edges will be set.
Cool cookies on cookie sheet for a few minutes before transferring to cooking rack to cool completely.