Start by whisking together the all-purpose flour, baking soda, cornstarch, cinnamon, and salt in a large bowl. This ensures a consistent distribution of the dry ingredients.

In another bowl, melt the butter and allow it to cool slightly. Whisk in the brown sugar until smooth and lump-free. Then add the egg and vanilla extract, mixing well. The aroma will already be irresistible!

Pour the wet ingredients into the dry mixture and gently mix with a spatula until a soft dough forms. The dough may feel sticky, but that’s okay. It will firm up during chilling!

Wrap the dough in plastic or cover your bowl, then place it in the refrigerator for at least 2 hours. This step is crucial for thick, chewy cookies.

Preheat your oven to 325°F and line your baking sheets with parchment paper. Roll the chilled dough into balls, about 2 tablespoons each. Roll the dough balls in granulated sugar for a sparkly finish.

Place the dough balls on the baking sheet, leaving space for spreading. Bake for 8-9 minutes, then gently press the tops with a spoon and return them to the oven for 2-4 more minutes. This gives them a lovely crinkled appearance.

Allow the cookies to cool slightly on the baking sheet before transferring them to a wire rack. Enjoy warm or store them for later!