01 -
Set the oven to 175°C and line baking sheets with parchment paper.
02 -
Combine softened butter, brown sugar, flour, cinnamon, and salt in a small bowl. Mix thoroughly and freeze for 10 minutes to firm.
03 -
Beat butter and granulated sugar together until the mixture is light and creamy. Incorporate vanilla extract, egg, and egg yolk, beating until smooth.
04 -
Whisk flour, baking powder, cornstarch, and salt together. Gradually add to the wet mix and beat just until combined, taking care not to overmix.
05 -
Divide the dough in half. Spread one half evenly in the mixing bowl. Add teaspoon-sized pieces of cinnamon sugar filling across this layer. Cover with the remaining dough half and press gently. Scatter remaining cinnamon sugar pieces on top.
06 -
Fold the layered dough and cinnamon sugar mixture gently twice by scraping and folding, followed by one to two gentle stirs with a rubber spatula to preserve the swirls.
07 -
Scoop dough into two-tablespoon sized balls, place on a tray, and freeze for 10 minutes to ensure minimal spreading during baking.
08 -
Arrange chilled dough balls on lined baking sheets and bake for 10 to 12 minutes until edges are golden and centers remain slightly soft.
09 -
Transfer cookies to wire racks and allow to cool completely before serving.