Sugar Cookie in a Cup

1 Tablespoon of Butter
2 Tablespoon of Granulated White Sugar
1/4 Teaspoon of Pure Vanilla Extract
Small pinch of Kosher Salt
Yolk of one Egg
3 Tablespoons of All-Purpose Flour
Colored Sugar for sprinkling


Melt butter in microwave, then add sugar, vanilla and salt and stir together. Add one egg yolk and stir again. Add flour and stir a final time.  Sprinkle cookie dough with colored sugar, and heat in microwave for about 45 seconds. Start checking for doneness at 40 seconds.