Homemade cookie in a cup dessert - Starts at 60

Ingredients

• 1 tbsp unsalted butter
• 1 tbsp granulated sugar
• 1 tbsp brown sugar, firmly packed
• 1/2 tsp vanilla extract
• 1/8 tsp (pinch) salt
• 1 egg yolk
• 3 tbsp all-purpose flour
• 1-2 tbsp chocolate chips