The Best Cinnamon Sugar Biscotti

🧂 Ingredients

• 6 tblsp butter

  softened
• 1 cup sugar
• 1 egg

  room temperature
• 1 egg yolk

  room temperature
• 1 tsp vanilla extract
• 2 cups flour
• 1 tsp baking powder
• 1/4 tsp salt
• 2 tsps cinnamon
• 1/4 cup granulated sugar
• 1 tsp cinnamon
• 1 egg

  lightly beaten