Beat the butter, powdered sugar and vanilla extract in a large bowl until the mixture is light and fluffy.
1.5 Cups Unsalted Butter, 1.5 Cups Powdered Sugar, 1 Tablespoon Vanilla Extract
Separately combine the all purpose flour, cornstarch, salt and cinnamon powder.
3 Cups All Purpose Flour, 2 Tablespoons Cornstarch, 1 Teaspoon Salt, 1 Teaspoon Cinnamon Powder
Add this dry mixture to the butter slowly and mix until the dough starts to stay together. You can gently knead the dough using your hand if it's crumbly.
Grease any pan of your choice or line it with parchment paper. Turn the dough into the prepared pan and gently press it to form an even layer.
Cut the dough into bars, wedges with a knife or into circles using a cookie cutter. Using a fork prick each bar twice at even spacing.
Preheat the oven to 150 C or 300 F. Freeze the dough while the oven is heating.
Prepare a mixture of granulated sugar and cinnamon. Sprinkle this over the cookies to coat them and gently press it in with your hands.
2 Tablespoons Granulated Sugar, 1/2 Teaspoon Cinnamon Powder
Bake the cookies in the oven for around 25-30 minutes, until they are light golden in color.
Cinnamon Shortbread Cookies are ready. Cool them completely on a wire rack before serving.