Chocolate Sugar Cookies

Ingredients

• 1 large egg
• 1 tsp pure vanilla extract
• 1 cup unsalted butter, at room temperature
• 1 3/4 cups all-purpose flour
• 1 3/4 cups sugar, plus 1 cup for rolling
• 3/4 tsp baking soda
• 1/2 tsp salt
• 1/2 cup cocoa powder